Comparison of visual functions without and with (iris-colored and transparent) soft contact lenses

Abstract

Purpose: To determine the effect of transparent and iris colored soft contact lenses on basic visual functions of human eyes. Method: In 50 eyes of 25 healthy emmetropes (11 males and 14 females) having age between 15-30 years visual functions i.e. visual acuity, contrast sensitivity, color vision, visual field and glare sensitivity were assessed with both transparent and iris colored soft contact lenses and compared with visual functions measured without wearing any contact lens. Visual acuity measured with Snellen acuity chart, color vision with Ishihara, contrast sensitivity on Lea symbols, visual field by using Confrontation method and glare sensitivity with the help of Brightness acuity test. Results: Visual acuity values were not significantly reduced with both transparent and iris colored contact lenses then without wearing them. Contrast sensitivity significantly reduced almost more than 1.25% with both transparent and colored contact lenses as compared to naked eye but no difference between transparent and colored contact lenses. Color vision is constant with and without wearing both transparent and soft contact lenses. Inferior visual field was partially reduced to very small extent with both transparent and colored soft contact lenses. Brightness acuity test results in decrease of visual acuity of one line more with both transparent and iris colored soft contact lens than without any contact lens after bright light stimulus. Conclusion: Contrast sensitivity and inferior visual field were significantly reduced and visual acuity values after bright light stimulus was lower with both transparent and iris colored contact lenses as compared without wearing any contact lenses. Key Words: Vision, Visual performance, Contact lenses.