The Effect Of The Echelon Bifocal Contact Lens On Contrast Sensativity And Brightness Acuity Testing.

Contrast sensativity and Brightness Acuity testing measurements with Hydron's Echelon Bifocal contact lens and Hydron's spherical non-bifocal contact lens were compared to learn the effect of the diffraction bifocal on contrast sensativity and glare. Six frequencies of sinusoidal gratings were generated with the Optronix Series 200 Vision Tester, a
microcomputer based test. Fifteen non-presbyopic subjects were tested for distance contrast sensativity and acuity.