Guided Meditation For Vision Acuity Training On Adolescent Myopia: Study Protocol For A Prospective, Multicenter, Randomized Controlled Trial

Background: Currently, the population with myopia climbs steadily, and developing toward younger age, posing a great concern to the health of adolescents. Myopia in severe cases can cause irreversible consequences such as glaucoma, blindness and other complications. At present, the solutions for myopia are glasses, medication and surgery. This study aims to investigate the role of a physiotherapy category based on guided meditation for vision acuity training on adolescent myopia. Methods: This is a prospective, randomized, multicenter clinical trial. 1140 primary and secondary school students aged 8-18 years old from 27 schools will be recruited and randomly divided into an experimental group and a control group at a ratio of 2:1 in two phases, with a training period of 30 days in each phase and a follow-up period of 3 months. No interventions will be conducted during the follow-up period, nor will other interventions employed. Inclusion criteria will meet the diagnostic criteria for simple myopia and -6.00D ≤ spherical lenses ≤ -0.50D, cylindrical lenses ≤ 1.50D. The primary observation index will be to compare the statistical differences in distant visual acuity between the two groups; the secondary observation indexes will be ocular symptoms (mainly including eye fatigue, dryness, pain, double vision, neck pain, thought disorders, and lags in response), diopter and astigmatism. Discussion: The purpose of this two-phase trial is to compare the clinical effectiveness of focused vision-guided meditation with Chinese eye exercises that are also non-pharmacological, non-invasive interventions for myopia, and to maximize the bene�t to the subjects. The results will indicate whether the training based on focused vision-guided meditation has the ability to improve distant visual acuity, relieve ocular symptoms and ameliorate diopter. In addition, this trial will provide clinical e�cacy of the training, which is expected to provide meaningful data for vision rehabilitation. At the same time, the vision acuity training method, which is permeated with the concept of Traditional Chinese Medicine (TCM) rehabilitation and health maintenance, will be applied to achieve the goal of preventing or alleviating myopic development and reducing myopia rate.

Myopia can be divided into simple myopia and pathological myopia. The most common one in adolescents is the simple myopia, which is induced by a combination of genetic and environmental factors, and is related to the weakening of visual regulation caused by spasm of the extraocular and ciliary muscles, which will gradually lead to the growth of the eye axis if it is not restored in time.
Therefore, the functions of the extraocular and ciliary muscles are crucial for maintaining good vision [5]. If not corrected in time, myopia will lead to serious and irreversible complications such as retinal detachment, macular degeneration, glaucoma, and blindness [6]. Strengthening vision protection for adolescents has become an urgent issue that needs to be addressed.
Currently, optical correction by glasses is the main intervention method for simple myopia, but it cannot improve visual acuity of the naked eye. Drugs such as atropine can improve visual acuity, but once the drug is discontinued, vision problem will rebound or causing even worsen myopia, along with some side effects such as photophobia, blurred vision and allergic conjunctivitis [7]. Laser surgery may be complicated by other eye diseases such as near vision impairment and dry eye, and has age restrictions [8,9].
Vision acuity training refers to the use of optical, psychological, physical and other methods to produce a certain cognitive load on the visual system of the eyes (including regulation, convergence, eye movements and the associated movements between them), in a bid to improve the visual function and visual comfort of the visual system and achieve the goal of improving and repairing visual abnormalities in both eyes. It is considered as a purely physical, non-invasive, non-drug therapy with no side effects to relieve eye fatigue and improve vision, with a long history. The earliest and most widely known is the Bates Vision Acuity Training Method, including eye sunbathing, palm massage, rope games, ruler games, pencil games, etc. But due to the complexity of its training, long cycles, etc., it has not been widely promoted. At present, the common vision training mainly relieves the ciliary muscle tension by repeatedly focusing on the distant visual target, looking at the distance and movement of the image to adjust the function of the extraocular muscles, and through the different light color changes to stimulate the visual cortex, as ways to improve vision and restore to a good visual system.
De ned as a form of training to improve concentration and mood, meditation involves a range of practices such as mindfulness meditation, yoga, tai chi and qigong [10]. Meditation is however not limited to sitting still; one can be in a meditative state while walking, standing, sitting, lying, or even working [11]. A recent article in the New England Journal of Medicine highly valued the contemporary value of meditation as "embarking on a new era in psychosomatic medicine" [12]. In recent years, meditation has attracted widespread attention and in-depth research across the world, mainly focusing on psychological diseases [13,14], pain [15], sleep disorders [16], chronic disease rehabilitation [17,18] and other elds. However, due to long intervention period, complex indicators, and di culty in objective quanti cation, it is di cult to fully re ect the effects of meditation.
The training based on Guided meditation for vision acuity belongs to a kind of regulation training method in the scope of physiotherapy, which mainly uses audio and video guidance to instruct myopia patients to focus on breathing, associate images, enter a meditation-like state and specialize the current practice.
Meanwhile, the patients could exercise the extraocular and ciliary muscles by incorporating simple actions such as hand-eye coordination with the stimulation of meridian points. In doing so, visual function and comfort can be improved. As this training method is simple and has a short period, it is welcomed by youngsters, and the indicators for evaluating vision acuity are simple, so it is easy to quantify the effect objectively.
Therefore, we will conduct a multicenter, randomized controlled study based on guided meditation for vision training. It is hoped that this study, from the perspective of psychosomatic medicine, can stimulate the self-healing ability in adolescent students under the guidance of external physical operations.

Ethics
This trial is designed in accordance with "Ethical Review of Biomedical Research Involving Human Subjects" issued by the Ministry of Health of the People's Republic of China. The implementation of this project has been reviewed and approved by the Ethical Review Committee of Beijing University of Chinese Medicine(4 June 2020, Approval Number: 2020 BZYLL0306). Written informed consent will be obtained from each subject and his/her guardian.

Study design
This study will be a prospective, multicenter, randomized controlled clinical trial. The included subjects (n=1140) will be randomly assigned to the experimental (n=760) and control (n=380) groups in a 2:1 ratio. The aim of this study is to objectively evaluate the clinical e cacy of the guided meditation of vision training for adolescent myopia. This report will be compiled according to the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) 2013 Statement 'De ning Standard Protocol Items for Clinical Trials' (Fig. 1).

Recruitment
In this trial, 1140 primary and secondary school students with simple myopia will be recruited from 27 schools in Sichuan and Hunan provinces or other cities with relatively uniform schooling conditions. The main points for the diagnosis of simple myopia in China's "Myopia Prevention and Treatment Guidelines" [19] will be used as a reference standard for recruitment: near visual acuity is normal , distance visual acuity is less than 1.0 (5.0 by the Mucosal method), there are no pathological changes in the fundus, the progression is slow, vision can be corrected to normal with appropriate lenses, while other visual function indicators are mostly normal; and the subject recruited meet the quantitative criteria for myopia according to the "White Paper on Myopia Prevention and Control" of the International Myopia Institute (IMI) [20] :
(3) Able to cooperate to complete the study.
(4) The subjects and their guardians must both voluntarily sign an informed consent form.

Exclusion criteria
(1) Those who have comorbidities or complications of other eye diseases, such as glaucoma, amblyopia, eye infections, etc.
(2) Those who have comorbidities of very severe heart, brain, liver, kidneys, hematopoietic system diseases and neuropsychiatric diseases, or systemic diseases that may affect the progression of myopia.
(3) Those who have had eye surgery or a history of eye trauma; (4) Those who have comorbidities of hearing abnormalities; (5) Those who are unable to cooperate with the study for personal or family reasons; (6) Those who refuse to sign an informed consent form by himself/herself or any of his/her guardians.

Withdrawal Criteria
Subjects have the right to withdraw from the study, as de ned in the informed consent document, or to "drop out" if they do not explicitly withdraw from the study but are no longer undergoing training and testing. The reason for withdrawal should be understood as far as possible, and recorded. For example, (1) perceiving lack of e cacy; (2) intolerance of certain adverse effects; (3) inability to continue the clinical study; (4) or lost to follow-up without explanation. Case record forms for withdrawn subjects will be kept and the results of the last trial will be considered nal. The data on the clinical e cacy and adverse effects of the focused vision-guided meditation training will be fully analyzed.

Suspension Criteria
The investigator will decide to terminate the study of a subject who has been enrolled in the study that the subject is un t to proceed the study. For example, (1) the subject develops certain comorbidities and complications under study; (2) the subject is un t to continue the study due to unexpected events or speci c physio-pathological changes during the study. (3) The subject meets the criteria for cure in less than 30 days, the study may be discontinued early if the subject so desires.

Excluded cases
Those who with any of the following should be excluded: (1) subjects with incomplete case information that affects the analysis of the trial results; (2) subjects with poor compliance during the trial due to subjective or objective factors of their own or family members; (3) subjects who uses other interventions for myopia outside the protocol.

Randomization
The random sequence will be designed and processed by the research team of Beijing University of Chinese Medicine. SPSS 20.0 (SPSS Inc., Chicago, Illinois, United States) software will be used to generate serial numbers for the subjects; the 1140 random numbers and the allocation sequence table with the unit are saved as blind codes. Subjects will be assigned to the experimental (n=760) and control groups (n=380) at a ratio of 2:1.

Allocation concealment
The randomization lists will be kept in opaque envelopes by the non-investigator on the team which are ordered, identical, and sealed with adhesive.

Implementation
The participants will be consecutively enrolled and distributed into experimental and control groups by researchers according to the randomized sequences generated who will not participate in assessing outcomes. Another group of researchers responsible for analyzing results will be blind to the grouping of subjects and will not participate in the treatment. The executors of this trial and subjects will not be blinded to the treatment assignment.

Interventions Explanation for the choice of comparators
The choice of the comparator is based on the current treatment of myopia in clinical.

Intervention description
The vision acuity training of this study is conducted in the schools, and school leaders are fully aware of this project, support and cooperate with the research work. Relevant teachers will be designated by the schools to be responsible for this project with respect to the speci c matters concerned. The study will be conducted in two phases over a period of 8 months, with a training period of 30 days in each phase and a follow-up of 3 months. No interventions will be conducted during the treatment period and follow-up period. One visual acuity examination will be performed in each of the two phases at months 1, 2, and 3 of the follow-up.

Phase 1
Experimental group Two sets of vision acuity training movement verbal commands will be applied in the experimental group. In order to facilitate the subjects to follow the verbal commands in a uniform, standardized way, the related audio and standard movements will be recorded.
The rst set of audio and video content are relatively rich, lasting about 1 hour, and the audio and video will be projected in the classroom on the rst and eighth day of training, with the subjects following the verbal commands and the movement demonstrations in the video. Visual training tutors (trained in procedures and methods) will be responsible for audio and video presentations.
The second set of audio and video content are relatively concise, approximately 15-20 minutes in length, and the subjects will be trained under the schools' uniform deployment for the remaining 28 days.
Due to the uninterrupted daily vision acuity training for 30 days, it is recommended to use the last selfstudy class at the schools to ensure that the students' normal studies are not interrupted; students will still be required to come to get trained at their school or a designated location con rmed with the schools on Saturday.

First training
The rst set of audio and video training exercises will be projected in the classroom by the vision acuity training tutor, and the students will be guided by the audio-visual movements and verbal commands to perform the following exercises.
(1) Abdominal breathing: Inhale through the nose, exhale through the mouth, bulge abdomen while inhaling, tighten abdomen while exhaling; start doing abdominal breathing when hearing the words of "adjust your breath and inhale.
(2) Eye-warning exercise: Rub your hands more than 30 times, cover your eyes with the palms, place thumbs on the temples, clasp four ngers on your forehead, and leverage the temperature of your palms to warm eyes; after the temperature gradually dissipates, use Yuji acupoints of the palms to gently press your eyes 5 times, with moderate intensity; start eye-warning exercise when you hear the words "get ready to press "and" quickly rub your hands" during training.
(3) Healthy vision exercise: Press both hands palms on your ears, place ngers on the back of your head; do not move the palms, and use ngers to gently tap the back of your head. During the training, when you hear "healthy vision exercise", start doing it.
(4) Activate Shixuan acupuncture point: Tap your ngers on your palm, shake your palm, and make an arrow shape.
(5) Play the "1-Audio", turn off the lights in the classroom, close the curtains, and try to create a dark environment. Remain quiet the entire time. Close your eyes until the audio says to open them. Follow the audio to imagine and do movements, e.g., "Use the ngertips of one hand to gently touch the center of the palm of the other, and then shake your hand vigorously.
(6) Play the "C-video", a video about lotus owers to stimulate the imagination and match the 2-Audio with the images that appear in the video. For example, "On a calm lake, you can de nitely see the vivid color of the lotus owers and the greenish-blue leaves of the lotus ......." (7) Demonstration and correction. Make a hollow bowl shape with your hands (thumbs on the second knuckle of your index nger) and clasp them over your eyes, with palms facing your eyes.
(8) Play "2-Audio" and do the eye stretches: Close your eyes and move them from front to back as if a train is moving back and forth in a tunnel.
(9) Play "3-Audio" and listen to the audio with your hands in a hollow bowl shape over your eyes the whole time. When the audio says "in", put pressure on your eyes for one second, and when it says "out", relax your eyes and perform the related imagery and actions. When the audio say "pull" in future exercises, let your eyes enter a state just like going into a tunnel, hold for 1 second, and then relax.
(10) Play "D-Video (Ball of Light)" to stimulate imagination and introduce natural light.
(11) Play "4-Audio" to build up the con dence of myopia sufferers to restore their eyesight.
The above training will be repeated on the 8th day to intensify the effect, for 1 hour.

Daily vision acuity training
Guided by the second set of audio and video movement verbal commands, the subjects perform selfrehabilitation exercises.
(1) Ocular exercises: keep body and head still, torso upright, move only eyes, four 8-tempos per part.
In the rst part, both eyes look up and down to the left. In the second part, both eyes look up and down to the right. In the third part, both eyes look to the left to the right. In the fourth part, both eyes turn clockwise. In the fth part, turn both eyes counterclockwise. In the sixth part, close your eyes hard and then open them to look up. In the seventh part, close your eyes for a moment to control the time.
(4) Character card stretching: 10 minutes of training, with results recorded on an observation chart. Character cards (Chinese characters of different sizes) are placed on a well-lit wall at the subject's eye level. Find the farthest place where you can see the card clearly, that is, about 10-15cm back where you cannot see the card clearly. Let your eyes stretch 6 times for 1.5 seconds each (eye movement, stretching backwards), without blinking, stare at the characters for 10 seconds, step back 15cm, and repeat the above movements until you are unable to see the location of the character card after stretching. If the training time is less than 10 minutes, switch to a second character and repeat the above steps; if it has reached 10 minutes, end the exercise and take notes.

Control group
The control group will be given Chinese eye exercises in the rst stage of the trial. On the rst day and the eighth day of the trial, the school teachers who has received training in Chinese eye exercises will give instructions on nding the positions of acupoints, massage intensity, direction and frequency according to the standard Chinese eye exercises Assessment Form to ensure that the students can perform the eye exercises independently and with high quality. For the remaining 28 days, subjects will be in a uniform classroom for 15-20 minutes of daily Chinese eye exercises. Acupoints: Jingming, Zanzhu, Yuyao, Tongziliao, Sizhukong, Taiyang, Chengqi, Sibai.

Second phase
After the completion of the rst phase of the randomized controlled study, data will be collected and compared between the vision acuity training group and the Chinese eye exercises group. If the data show that the vision acuity training is not signi cantly better than the Chinese eye exercises, the trial will be terminated; if the data show that the vision acuity training is signi cantly better than the eye exercises, the trial will enter the second phase, and the 3-month follow-up period of the rst phase will be used as an elution period before the second phase. In the second phase, the experimental group will end the trial, and the control group will switch to a 30-day vision acuity training method based on meditation and concentration, with a follow-up period of 3 months.
The subjects in this study are adolescent students with simple myopia and no other comorbidities of chronic diseases. If the subjects need to combine medication due to cold or other reasons, they should be recorded promptly.

Basic Information Collection
Information will be collected from the subjects before the start and after the trial is completed, and the main information is as follows. a. Basic information: age, nation, grade, height, weight, family history of myopia, parents' high myopia, etc.
b. Myopia: duration of myopia, possible causes of myopia, naked eye visual acuity, corrected visual acuity, diopter of both eyes, astigmatism and so on.
c. Time allocation for daily activities: including close range activities (<50 cm): such as drawing, homework, reading and using electronic screen terminals such as mobile phones; outdoor activities: including playing outdoors, cycling, hiking, etc.
Primary observation indexes vision acuity training aims to improve the visual acuity of the naked eye that affects life and work, so this study will use distance visual acuity as the primary observation index. After the start of the training, visual acuity tests will be performed before and after daily training for the rst 7 days; after 7 days of training, visual acuity tests are performed once a week; and the tests will be performed at the 1st, 2nd, and 3rd months of follow-up.
The speci cation for visual acuity testing is based on the "Expert Consensus on Work ow of Myopia Screening in Children and Adolescents (2019)" [21]. Measurements are taken under adequate lighting conditions and the subjects are measured 5 meters away from the visual acuity meter. All visual acuity examinations in this study will be performed by a regular person who will not undergo vision acuity training or clinical examinations. Speci c details of subjects will be not disclosed to this measurer.

Secondary observation indexes
Ocular symptoms, diopter and astigmatism are secondary indexes. Ocular symptoms will be evaluated before and after 30 days of training, respectively. Diopter will be obtained from the subjects after testing at the same hospital before and after the training.
Ocular symptoms a. Ocular symptom scores are developed based on the "Visual Fatigue Test and Evaluation Method (VFTEM)" and principally cover eye fatigue, dryness, pain, visual double vision, neck pain, thought disorders, and lags in response.
b. Collective Insu cient Symptoms Survey (CISS): the CISS is a valid tool in quantifying near visual acuity symptoms in adolescents [22] and consists of 15 items, each with ve options of varying degrees, scored as follows: never (0), rarely (1), sometimes (2), often (3) and always (4). The sum of the 15 items' scores (ranging from 0 to 60) is the total score. All of the above information and scales need to be completed with the help of the subject student's parents and professional staff.

Diopter and astigmatism
The diopter (after pupil dilation by tropicamide) and astigmatism will be obtained from the students after examination at a local rst-tier public hospital or public eye hospital accompanied by their family members, and the data will be recorded in the entry of "Information Collection -Visual Acuity".

Data Entry and Statistical Analysis
Data collection A paper version of the Case Report Form will be developed for data collection. The data will be collected using standardized entry terms and structured registration contents as much as possible, which will facilitate post-processing and analysis of the data and minimize the burden on the researcher. According to the original observation records of the subjects, the data manager will load the data into the case report form in a timely, complete, correct and clear manner. When amending a case, the original record should be clearly visible, and corrections should be signed and dated by the investigator.

Data entry and storage
The paper-based data should be entered by a dedicated data manager using a dual-track entry to reduce the error rate, and any problems or unexpected matters found in the entry process should be registered and reported promptly so that problems can be dealt with quickly. Observation forms should be subject to random inspections at the end of data entry to understand the quality of the entry and to analyze and address any problems. Once data entry is completed, all original case report information should be kept. The original case report forms, after completion of data entry and veri cation as required, should be led in a numbered order, and a dedicated person should be assigned to manage the les and complete the search directory, etc. Also, the entered data should be backed up regularly to prevent loss of data and other unexpected occurrences. Particular attention should be paid to the security of data storage and the protection of the privacy of the subjects and related personnel. All research documents will be stored in special ling cabinets that are locked to ensure the security of the stored documents. In any case, only authorized staff will have access to the data.

Sample size
The sample size of this superiority trial will be estimated based on the past research [23]and early observations. According to the references and professional judgment, it is assumed that the effective rates of the control group and the experimental group will be 40% and 51%, respectively. Under 20% dropout rate, if the two-tailed α=0.05 and β=0.1 test e cacy of 0.9 , experimental group: control group = 2:1, and the dropout rate is 20%, then it will be calculated through the following formula: It's nally con rmed there will be 1140 cases in total, with 760 cases in the experimental group and 380 cases in the control group.

Statistical analysis
Statistical analysis using SPSS 20.0 will be performed, and data management software will be used to construct the database. Dedicated staff will be assigned to oversee the management of electronic data, and a clinical research team will be deployed for data entry, validation, reporting, and answering questions. Measurement data will be described statistically using mean ± standard deviation and counts will be described statistically using frequency. Measurement data conforming to a normal distribution will be compared between groups using two independent samples t-test in randomized controlled study and paired samples t-test in pre-post controlled study. P ≤ 0.05 will be considered a statistically signi cant difference.
Primary and secondary observation indexes will be analyzed by the superiority test depending on the treatment, using Per Protocol Set (PPS) and Full Analysis Set (FAS) datasets. The indices of safety evaluation will be analyzed using the Save Set (SS) dataset.

Monitoring
A Data Monitoring Committee DMC will be instituted during the study, which is consisted of project researchers, ethics committee members, statistical analysis personnel, and implementation teachers.
Who have no competing interests. It is the responsibility of the DMC to review the trial design and trial documentations prior to the commencement of the study to identify issues that may affect data analysis or patient safety. And identify problems during project implementation and take timely intervention measures. The collected data will be checked again at the end of the study.

Adverse events
In case of any adverse event, subjective discomfort (dizziness, nausea, etc.) or abnormal laboratory parameters of subjects should be treated seriously, the cause should be carefully analyzed, and immediate measures should be taken to maintain the safety of the subject's life. Procedures: Detailed records should be made on the case report form, and retesting should be performed within 24 hours, 7 days, and 14 days as appropriate. Records of persistence, prognosis and disappearance should be kept.
Treatment of serious adverse events: If there is any serious adverse event in the course of the study, it must be reported immediately to the ethics committee of the organization, and the sponsor, and the "Serious Adverse Event Report Form" must be lled; if there is a serious adverse reaction, it should be reported to the National Medical Products Administration within 24 hours, and the contact person should be noti ed according to the telephone number and home address listed in the case report form.
(1) Treatment measures: When the subject has an accident or emergency, the investigator should make corresponding treatment according to the experimental therapy and its symptoms, and pass the treatment results to the clinical examiner. The institute should record the treatment and results on the case report form and sign it.
(2) Follow-up of unmitigated adverse events: all adverse events should be tracked for their cause until they can be appropriately resolved.
Frequency and plans for auditing trial conduct The DMC and the ethics committee will meet annually during the trial to review the conduct of the study, Good Clinical Practice(GCP), compliance with the protocol standard operating procedures and applicable regulatory requirements.

Quality control
Quality control is crucial to the reliability and accuracy of the research results, mainly conducted over the implementation process and data management aspects to achieve quality assurance. Quality control principally covers the following aspects: 1. investigator training: before the implementation of the study, a detailed research protocol and the SOPs should be developed, participants of the study should be trained and documented; 2. data quality control: investigators should be trained, and the way in which data are collected, the list of all data elements and de nitions, and the treatment methods for missing values, invalid entries, incorrect entries, and logically inconsistent data should be clari ed during training. To prevent data bias, data entry and statisticians should be masked during the trial.

Con dentiality
This study will fully comply with the relevant provisions of the data protection legislation. All appropriate and necessary precautions will be taken to keep medical data and personal information permanently con dential.

Discussion
The eyes do not exist in isolation, but are an integral part of what makes up the human body, in uencing the body, mind and emotions in a unique way. Western medical research has shown that the visual system is considerably sensitive to any form of stress, tension and mental state, and that vision problems usually occur along with chronic stress and incorrect eye habits. Nearsightedness, farsightedness and astigmatism are symptoms that are resulted from this underlying stress and imbalance. A better holistic model of vision includes the following three components: Physical Eyesight, Inner Vision, and Emotional Seeing [24].
The book "Zhu Bing Yuan Hou Lun", also known as "General Treatise on Etiologies and Manifestations of All Diseases" from Traditional Chinese Medicine (TCM) states: "The injury to the visceral organs caused by fatigue, de ciency of liver vitality (qi), and exposure to exopathic evil (wind-evil) make the essence of qi or vitality weak, causing vision problems", pointing out the causalities and characteristics of myopia in a systematic way. The liver is the main reservoir of blood and one of the major sources for vitality, associating strongly with blood capillary supplement for extraocular muscle. Emotion uctuation as well as excessive use of eye will compromise liver qi (vitality) or cause it to be stagnant, thereby affecting blood or qi supply to the eye, leading to vision problems. "The Chapter of Discussion on the Generation of Five Zang (visceral) Organs in Su Wen" states: "the heart governs blood vessels, all vessels connect to the eyes."; spleen is the origin of acquired constitution and the source of qi and blood production; if the spleen qi suffers from de ciencies lasted, blood is di cult to nourish eyes, compromising the visual acuity. According to Zhang Jingyue, an ancient TCM master, "lung governs qi, and when qi is coordinated, de ciencies in nutritive qi and protective qi as well as lower vitality in zang (visceral )-organs are all cured"; The whole body's blood converges at the lung, and lung regulates the whole body's vigor of qi; when the qi of the lung is harmonized, blood can form a steady ow into the eyes, thus bene ting the vision; Thus, the de ciency of essence of visceral organs will dampen the vigor qi for blood ow and make it unable to nourish eyes, thereby weakening the vision; from the clinical perspective of Chinese medicine, the causalities of vision problems are related to liver, heart, spleen, lung and kidney, the ve zang (visceral) -organs [25]; Therefore, vision rehabilitation training should not be limited to the adjustment of the visual system only, but extend to internal, external treatments, as well as physical and physiological regulation holistically.
Meditation is vital for "mental condition adjustment" and "health improvement" in TCM, and has been advocated and practiced by medical practitioners in ancient China. It is also one of the populated approaches for self-health management. Meditation is often coordinated with the adjustment of posture, breathing and consciousness to motivate self-healing capacity. It means to build a peaceful and perceptive mind to overcome the judgmental thoughts or emotions; This helps to eliminate unhealthy muscle memories and psychological preconceptions, potentially creating new ways to cope with illness [26]. Studies have shown that during meditation, parasympathetic activity increases, sensory and perceptual changes occur. These physiological changes are a state of self-healing relaxation that may have preventive and therapeutic effects on human health [27]. Meditation is also a positive mental exercise that alters brain and mind function and facilitates the regulation of attention, cognition and mood. It is well documented that mental state affects physical condition, and its imbalance affecting hormone release, attributing to diseases.
The incorporation of meditation elements into vision acuity training is a multifaceted combination of movement, breathing and imagination, which may enhance vision by strengthening the eye muscle regulation functions. This project will be conducted in two phases, using two research designs. The rst phase will be a multicenter randomized controlled study, and the second phase will be a single-arm pre-post controlled study. The aim is to compare the differences in the effects of the training based on guided meditation and Chinese eye exercises on vision regulation in adolescents. If the signi cant clinical e cacy and safety are uncovered, a novel non-pharmacological physical therapy will be provided for the treatment of adolescent myopia. The study will also help to promote and disseminate the vision acuity training method, which is infused with the TCM rehabilitation concept, and provide a reference plan and basis for solving the myopia problem among adolescents.

Declarations
Trial status be obtained from all participants or their authorized representatives.