Application of a New Device for Vision Relaxation in Computer Users

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This is a detailed study of the efficacy of a novel technology, with a comprehensive set of tests, a large sample and appropriate control groups. The methods are clearly explained.

 

I have some questions of clarification regarding the results

 

 

Ages vary quite noticeably across the groups. How does this affect the conclusions, given known age effects on visual function?

 

The changes in visual acuity seem unexpected, given that they occurred for all groups, and over a relatively short period. This raises some concerns about the overall reliability of the data. While I don’t doubt the results, the statistical power appears to be picking up on some random drift, so I would suggest that any result that we want to relate causally to the interventions would need evidence that goes above this (e.g. large effects, or ways in attributing causality). 

 

This is only my preference – but I would find if easier if the groups had meaningful names (e.g. control, manual training, eyeroll). The A,BC labels add an unnecessary memory load to decode.

 

The same is true for the testing times, which are referred to using different labels (1^st, 2^nd and 4rd visit, and 4-week , 8-week.). Sticking to baseline, 4-week, and 8-week labels would be much clearer. 

 

Does the group difference in accommodation reflect group differences unrelated to the training? Might this be explained by the age difference across groups? Also, it seems odd that the only difference found was for group A (control), whereas we might have expected differences in B and C. One possible explanation for the lack of effect in the latter two groups might be age (although the groups are still quite young), but it is not clear why there might be differences for group A. Given the small numbers I suspect these are spurious effects.

 

There is quite a lot going on in the saccade data (including for group A). Again this suggests that some of the results might be random fluctuation. To help understand this, is it possible to be clearer about what might have been predicted, or whether there is a meaningful interpretation of the changes presented?

 

 

 

Author Response

We thank the reviewer for the valuable comments. This has much improved our manuscript. Below, we listed the original comments from the reviewer and our responses. We hope all questions are sufficiently answered. The page numbers with line numbers are added to refer to the highlighted (coloured in yellow) changes in the revised manuscript version.

1. Ages vary quite noticeably across the groups. How does this affect the conclusions, given known age effects on visual function?

Answer. Thank you for emphasizing this issue. We agree that the age varies widely across the groups. However, we believe the results were not affected by the age variability. First, we had a strict inclusion criterion regarding visual acuity and subjective correction; we included only those participants that had (1) a best corrected visual acuity (BCVA) of 0.8 (in decimal units) for both near and distant vision, (2) no ocular or systemic diseases, and (3) already had their vision correction (if required at near and/or distance). Thus, we ensured that all participants involved in the study do not have their complaints due to lack of subjective refraction or near addition in case of presbyopia. Second, the latest stadies (Elliott et al., 1995; Martinez-Roda et al., 2016) demonstrate that visual acuity, as well as other visual functions start to decline after the age of 50. Third, we had only three participants after the age of 40 and only one was at the age of 50. Thus, the most of our participants were up to the age of 40. Finally, the Spearman’s rank-order correlation demonstrated negative weak but signifficant correlation between the age and score of complaints on the baseline visit (r_s = -0.256, P = 0.017). Thus, there are even less complaints with increasing age. We also observed that younger persons are less interested in the performance of various vision relaxation exercises even if they have asthenopic complaints after near work. In contrast, it was the over-30s who were more interested in performing various vision-enhancing tasks and, in particular, in using different devices. In summary, we are confident that the age variation of the participants did not affect the findings, either in terms of complaints or visual function.

We included this considerations in the discussion. See Page 19-20 lines 697-709.

References:

• Elliott, D.B., Yang, K.C.H., & Whitaker, D. (1995). Visual acuity changes throughout adulthood in normal, healthy eyes: seeing beyond 6/6. Optometry and Vision Science, 72(2), 186-191.
• Martinez-Roda, J.A., Vilaseca, M., Ondategui, J.C., Aguirre, M., & Pujol, J. (2016). Effect of aging on optical quality and visual function. Clinical and Experimental Optometry, 99(6), 518-525.

 

2. The changes in visual acuity seem unexpected, given that they occurred for all groups, and over a relatively short period. This raises some concerns about the overall reliability of the data. While I don’t doubt the results, the statistical power appears to be picking up on some random drift, so I would suggest that any result that we want to relate causally to the interventions would need evidence that goes above this (e.g. large effects, or ways in attributing causality). 

 Answer. Thank you for your comment. We agree that the statistical effect may have been caused by random effects. However, we believe that although the statistics indicate a significant improvement, the variation in visual acuity may have other explanations, which we explore in the discussion (Page 19 lines 648-661).

3. This is only my preference – but I would find if easier if the groups had meaningful names (e.g. control, manual training, eyeroll). The A,BC labels add an unnecessary memory load to decode.

Answer. Thank you for your suggestion. To make it easier for readers to follow the research process, we changed the names of all groups to Control, Manual, and Eyeroll.

4. The same is true for the testing times, which are referred to using different labels (1^st, 2^ndand 4rd visit, and 4-week , 8-week.). Sticking to baseline, 4-week, and 8-week labels would be much clearer. 

Answer: Thank you for your suggestion. We reviewed the manuscript and corrected all testing times to keep the same labels throughout the manuscript: baseline, 4-week, and 8-week.

5. Does the group difference in accommodation reflect group differences unrelated to the training? Might this be explained by the age difference across groups? Also, it seems odd that the only difference found was for group A (control), whereas we might have expected differences in B and C. One possible explanation for the lack of effect in the latter two groups might be age (although the groups are still quite young), but it is not clear why there might be differences for group A. Given the small numbers I suspect these are spurious effects.

Answer: Thank you for this question. We agree that the effect is due to the small number of participants. Regrettably, the equipment used for objective accommodation assessment (PowerRef3) imposes several limitations, with the most significant being the potential for measurement errors caused by the use of spectacle correction during the process. Therefore, we must make all measurements either without correction or with contact lenses. Unfortunately, if the participant has never worn contact lenses, using them during the measurement may cause additional difficulties (increased tearing, blinking, and discomfort). In addition, we lacked access to a complete set of contact lenses suitable for each participant. Therefore, for several participants in the study, it was not possible to take measurements, or the measurements obtained were not interpretable. Consequently, the number of participants who underwent objective measurements of accommodation was also limited. The second factor that explains why the accommodation response was different in the control group compared to the two training groups is the refraction-accommodation factor. This factor indicates that, in the absence of correction, hypermetropic participants will accommodate more than emmetropic participants. On the other hand, participants with myopia will accommodate even less than those with emmetropia, with the amount of accommodation decreasing as myopia increases. The control group had more participants with hypermetropia (4/6). Therefore, we observe higher values of accommodation in this group. On the other hand, myopic participants (Manual: 12 myopia, 3 hyperopia, 7 emmetropia; Eyeroll: 6 myopia, 1 hyperopia, 2 emmetropia) dominated both training groups and had lower accommodation responses as a result.

The effect of age will be less significant in this case, as although there was age variation between groups, none of the groups measuring accommodation had participants over 40 years of age. At this age, there is a noticeable physiological decline in accommodation. However, the study design and careful selection of participants with both distance and near visual acuities that meet the study requirements suggest that physiological decline could not have affected these measurements.

Therefore, the small number of participants and the uneven distribution of refraction could primarily explain the differences and changes in the accommodation response after 4 weeks in the control group. In order to gain a deeper understanding of the changes in the objective parameters following the vision relaxation exercises, we should increase the number of participants, modify the study design to include more individuals with appropriate vision correction, particularly contact lenses, and ensure an equal distribution of all types and degrees of refraction among the groups. In this scenario, we suggest conducting a study that evaluates accommodation both before and after the relaxation exercises on the same day and tracks any alterations in accommodation over a longer time period.

We explored this limitation in discussion section Page 19 lines 672-696.

6. There is quite a lot going on in the saccade data (including for group A). Again this suggests that some of the results might be random fluctuation. To help understand this, is it possible to be clearer about what might have been predicted, or whether there is a meaningful interpretation of the changes presented?

 Answer: We signifficantly condenced the subsection about saccadic movements to emphasize only the most important information (see Pages 13-16). In addition, we reviewed the discussion part and considered the observed changes as a random fluctuations in the sacadic response. However, we believe that the main reason for such changes is related to stimuli used in the EYE ROLL device that is similar to clasically used stimuli for saccadic training. We agree that additional study is required to explore the potential of the EYE ROLL device in enhancing eye movements. See Page 20, lines 722-727 and 736-738.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The study presents an innovative approach to addressing computer vision syndrome by evaluating the effectiveness of the EYE ROLL device in facilitating vision relaxation exercises. The research is well-structured and provides a thorough analysis of the impact of these exercises among computer users.

Some specific comments:

1.Introduction part: effectively sets the context for the study, highlighting the prevalence of CVS and the need for effective interventions. However, a more detailed review of existing vision relaxation techniques and their limitations could further justify the need for the EYE ROLL device.

2. Materials and Methods:

This section is detailed and clear. However, it would benefit from a flowchart or diagram illustrating the study design and participant flow to enhance clarity. too much textual descriptions.

 

The original text provides a detailed introduction to each group's composition and follow-up time points, which should be succinctly summarized by combining the information.

3. Data Analysis and Results Presentation

Overly detailed. The main results and findings should be retained, while other parts need to be appropriately condensed. There is no need to include every statistical test and specific values from the original data analysis section.

4. Discussion and conclusion:

The discussion appropriately interprets the findings, linking them to existing literature. However, a more critical analysis of the study's limitations and suggestions for future research directions should be clearly stated, including more balanced distribution of participants, long term effects, and additional objective measures of visual discomfort more than relies on self-reported questionnaires.

The conclusion mainly summarizes the findings and practical implications. Specific recommendations for future research will strengthen this section.

Comments on the Quality of English Language

Overall, the language quality is high, but readability and conciseness can be improved through simplification. Some paragraphs are densely packed with information, affecting overall readability.

Author Response

We thank the reviewer for the valuable comments. This has much improved our manuscript. Below, we listed the original comments from the reviewer and our responses. We hope all questions are sufficiently answered. The page numbers with line numbers are added to refer to the highlighted (coloured in yellow) changes in the revised manuscript version.

1. Introduction part: effectively sets the context for the study, highlighting the prevalence of CVS and the need for effective interventions. However, a more detailed review of existing vision relaxation techniques and their limitations could further justify the need for the EYE ROLL device.

Answer: We appreciate your suggestion. We agree that there are several vision relaxation techniques all of which, however, are based on the same basic principle, which is to rotate the eyes and change the fixation distances and points. In our manuscript, we mainly concentrate on the special programmes that are designed to offer guidelines for vision relaxation. The primary function of such programmes is to serve as a reminder of the necessity of taking regular breaks during the near work. During the breaks, they present visual activities that can be completed on the screen or by following the written or illustrated instructions. Hence, their main limitations are related to the performance, i.e. either there are specially designed images on the screen, or the user must constantly glance back at the screen to read the instructions for the next exercise. This methodology contrasts with the recommendation for computer users to shift their gaze away from screens for optimal relaxation. As there is still a desire in society to use various assistive devices and no tools are available to guide proper relaxation vision exercises, the EYE ROLL device was developed. We reviewed the current description of existing vision relaxation techniques in the Introduction and updated it. However, we avoided too broad description so as not to unnecessarily increase the length of the manuscript. We hope that the improved description better justifies the need for the EYE ROLL device.

See Page 2, lines 74-88.

2. Materials and Methods: This section is detailed and clear. However, it would benefit from a flowchart or diagram illustrating the study design and participant flow to enhance clarity. Too much textual descriptions. The original text provides a detailed introduction to each group's composition and follow-up time points, which should be succinctly summarized by combining the information.

Answer: We added Figure 1 (Page 3) that illustrates the study design and participant flow.

3. Data Analysis and Results Presentation: Overly detailed. The main results and findings should be retained, while other parts need to be appropriately condensed. There is no need to include every statistical test and specific values from the original data analysis section.

Answer: Thank you for this suggestion. We have re-read everything and tried to shorten the text accordingly. We removed unnecessary statistics from the text to make it more fluent in reading and not so overhalmed with numbers. However, the statistical analyses result was included in the tables showing the statistical tool used and the p-value with the corresponding symbols. See Table 4 and text desccription on Pages 9-13 (marked yellow). Especially, we signifficantly condenced the subsection about saccadic movements to emphasize only the most important information (see Pages 13-16).

4. Discussion and conclusion: The discussion appropriately interprets the findings, linking them to existing literature. However, a more critical analysis of the study's limitations and suggestions for future research directions should be clearly stated, including more balanced distribution of participants, long term effects, and additional objective measures of visual discomfort more than relies on self-reported questionnaires. The conclusion mainly summarizes the findings and practical implications. Specific recommendations for future research will strengthen this section.

Answer: Thank you for this suggestion. We added recommendation for future studies in the conclusion and looked more critically on the study’s limitaitons in the discussion part.

See Discussion Pages 18-20 (lines 643-647, 659-661, 672-709, 736-738) and Conclusion Page 21 (lines 754-759).

5. Comments on the Quality of English Language: Overall, the language quality is high, but readability and conciseness can be improved through simplification. Some paragraphs are densely packed with information, affecting overall readability.

Answer: Thank you for this suggestion. We have reviewed the whole manuscript and tried to simplify some text parts to simplify the readability (especially presenting our results).

Author Response File: Author Response.pdf