MYOPIA AND BINOCULAR VISION FUNCTIONS AMONG ALLIED HEALTH SCIENCES STUDENTS AT IIUM

Abstract

Myopia is believed to have some effects on lag of accommodation, heterophoria and AC/A ratio.  Previous studies reported that the lag of accommodation of myopic is higher compared to an emmetropic eye. It is also reported that the incident of exophoria in myopic eyes is more common compared to emmetropic eyes. Additionally, myopic individuals are anticipated to exhibit higher accommodative convergence compared to emmetropic individuals. This study aimed to investigate these effects on undergraduate students of Kulliyyah of Allied Health Sciences, particularly assessing how different the degrees of myopia impact these visual functions. The lag of accommodation, heterophoria and AC/A ratio of 82 participants were measured with full correction. The lag of accommodation was measured utilizing an autorefractor, Grand-Seiko WR-5100K while the heterophoria measurement was obtained by using the Howell Card and the AC/A ratio was measured by using the gradient method. The results revealed a significant difference in lag of accommodation between myopic and emmetropic students, but no significant differences in heterophoria and AC/A ratio between the two groups. When comparing various degrees of myopia, only the lag of accommodation showed a significant difference, while AC/A ratio and heterophoria remained unaffected. In summary, myopia primarily affects the lag of accommodation, with no significant impact on AC/A ratio and heterophoria in KAHS students’ population. Thus, it is predicted that the possibility of myopia progression on these subjects are very low.