## 5 Conclusions  
Our study has provided comprehensive insights into various facets of colour vision and its association with digital device usage and COVID-19 infection. Here, we present a detailed summary of our key findings and their implications:  
Absence of Relationship with COVID-19: Our investigation revealed no discernible link between COVID-19 infection status and the development of acquired colour vision deficiencies. This finding contributes to the growing body of knowledge regarding the diverse manifestations and sequelae of COVID-19.  
Digital Device Screening and Colour Vision Deficiencies: Contrary to concerns regarding prolonged screen exposure, our study found no significant relationship between the duration of digital device screening and the incidence of acquired colour vision deficiencies. This finding allays concerns regarding the potential adverse effects of excessive screen time on colour vision health. This study marks a pioneering effort in investigating the relationship between screening time and colour vision capacity. While our initial findings suggest no detrimental effects of prolonged digital device usage on colour perception, further research is warranted to validate and elucidate these preliminary observations.  
Gender Neutrality in Acquired Colour Vision Deficiencies: Gender-based differences in the colour vision capacity of normal trichromats were not observed in our study, highlighting the uniformity of colour perception abilities across genders.  
Validation of Digital Ishihara Test: The comparable performance of the Ishihara Test administered on physical and digital platforms validates the utility of online Ishihara testing, particularly on devices such as the iPad 12 mini, for detecting congenital colour vision defects. This validation expands the accessibility and convenience of colour vision screening methods.  
Confirmation of Smartphone Usage Patrons: Our study corroborates existing literature documenting the exponential increase in smartphone usage among young adults. By quantifying the average smartphone usage time within our study cohort, we provide empirical evidence of this prevailing trend, emphasising the need for continued research into the potential implications of extensive digital device use on various aspects of health and well-being.  
Population Representation and Generalizability: The studied population, comprising healthy individuals aged 20 to 30 years, offers a representative sample for examining colour vision phenomena within this demographic segment. The inclusion of both the Ishihara Test and the Farnsworth-Munsell 100-Hue Test enhances the robustness and applicability of our findings within this population subset.  
In summary, the study contributes valuable insights into the multifaceted interplay between digital device usage, COVID-19 infection, and colour vision health. These findings hold implications for public health initiatives, clinical practice, and future research endeavours aimed at elucidating the complex mechanisms underlying colour vision acquired deficiencies and its modulation by mentioned environmental factors.  
Conceptualization, M.M.S. and I.T.M.; methodology, M.M.S.; software, J.J. and B.M.; validation, D.L. and G.P.-F.; formal analysis, M.M.S.; investigation, M.M.S. and I.T.M.; resources, I.T.M.; data curation, B.M. and D.L.; writing--original draft preparation, M.M.S.; writing--review and editing, M.M.S.; visualization, G.P.-F.; supervision, I.T.M.; project administration, M.M.S. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Informed Consent Statement: Informed consent was obtained from all subjects involved in the study.  
All the data analyzed in the study can be found published in the papers included in the bibliography and references. It is not necessary to consult additional data sources to obtain it.  
The authors declare no conflicts of interest.