Colour Vision Changes across Lifespan: Insights from FM100 and CAD Tests
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript by Trukša et al. “Color Vision Changes Across the Lifespan: Insights from FM100 and CAD Tests” examines a comparison between the FM100 test and the CAD test in their ability to detect color deficiencies in different age groups. The results did not show an increase in chromatic sensitivity of the red-green visual axis with age but did show an increase in the blue-yellow axis with both tests. Based on these results, the authors confirm the data obtained by Beirne et al., 2008 with FM100, who observed an increase in the number of PES along the blue-yellow axis with age but could not confirm it statistically due to the small number of participants.
Although the FM 100 test is known to be a sensitive test for mild color deficiencies, including acquired ones, the results in the present manuscript show that FM 100 could miss some mild color deficiencies in the red-green color axis. The authors conclude that the CAD test is more effective than the FM 100 for detecting mild color deficiencies and can be used as an alternative to the anomaloscope because of its simpler instructions.
The paper is well-written, and the results are well-explained to support the claims of the authors. I only have minor comments to offer about the methods.
The methods are described very briefly. It is unclear whether the participants underwent an ophthalmological examination to identify eye diseases that would prevent them from participating in the study. It is also important to ensure that subjects who needed optical correction wore lenses or glasses that did not change the color or intensity of light. Was this observed?
It would be beneficial to provide a brief description of the conditions under which the tests were conducted. For instance, it is important to outline the characteristics of the lightbox used for the FM100 test and specify if Farnsworth's (1980) original instructions for conducting the test were adhered to. Additionally, it would be helpful to know the time allocated for each box or if the subjects were allowed to take as much time as necessary to complete the box.
Author Response
"Please see the attachment."
Author Response File: 
Author Response.docx
Reviewer 2 Report
Comments and Suggestions for AuthorsThank you for the paper. I found the structure of the paper difficult to follow as you have multiple hypotheses and your methods of analyses and their rationale were not clear. However the results have value so these comments are in the spirit of improving clarity.
1. Wish to compare if the results are correlated for different colour vision tests? Advantage of CAD is multiple directions assessed. Rationale for analysing by direction. Is unclear, might be better to determine whether including increasing numbers of colour directions is useful? Or which is most comparable or correlated with fm100 hue results?
2. How colour directions were defined was unclear. Please present as you do for fm 100 hue so comparability is more obvious to the reader eg with a diagram
3. Figure 4a x axis label has a spelling error obscuring meaning
4. Rationale for analyses were unclear.
5. Argument for why fm100 hue is superior to CAD is not well argued. Could compare sensitivity and specificity for multiple key measures from 4a instead of only one. I think the main argument is that testing additional directions aids in sensitivity and specificity so why not pool the results you are interested in from both the cad and 100 hue? Or at least discuss this.
Comments on the Quality of English Language
Appropriate but rationale needs better articulation .u
Author Response
"Please see the attachment."
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsI am satisfied with the responses. Thank you.
Reviewer 2 Report
Comments and Suggestions for AuthorsThank you for this much improved manuscript. The hypotheses and results are clearly presented.
