خلاصة:
Purpose: To investigate the effects of wearing hydrogel lenses on daily wear basis for long period (year) on the visual functions in Sudanese young adult subjects. Methods: A descriptive cross sectional, case control study was conducted among 63 neophyte (who never worn contact lens before) volunteer students in Faculty of Optometry. All subjects were fitted with hydrogel soft contact lenses (CLEVIO) (water content 38%) POTEC Co.LTD for one year. Selected with best corrected visual acuity, contrast sensitivity, binocular vision (stereopsis), normal colour vision and central visual acuity. Results: Repeated measure analysis of variable (ANOVA) was used to find is there any significant mean differences in contrast sensitivity, stereoacuity ,colour vision and central visual field measurements with hydrogel contact lenses wear during the time of the study (i.e. baseline, 2 weeks, 1 month, 3 months, 6 months and 12 months). The test yielded significant reduction in contrast sensitivity values with contact lens wear during the study period, F = 157.44 , P < 0.001. Analysis of variables also showed significant reduction in means of stereoacuity measured with contact lenses during the study period, F = 3.70, p = 0.003. There was no change in colour vision and central visual field during sessions of the period study. Conclusions: The wearing of hydrogel soft contact lenses for long periods (one year) showed significant drop in contrast sensitivity values and in stereoscopic vision. There was no change in colour vision and central visual field during sessions of the period study. The study also showed that there was no or little reduce in contrast sensitivity and stereoacuity in early period of the study (up to 1 month).