PERFORMANCE OF A COLOR INDICATOR IN A DISINFECTING SOLUTION FOR THE MAINTENANCE OF SOFT CONTACT-LENSES

An experimental study of Allergan's Oxysept Comfort system was perform ed by measuring the slight reddish hue that appears in the disinfectin g solution, indicating to the users that their lenses are again ready to be worn. The temporal evolution of the color of the solution has be en measured under standardized conditions and analyzed in the CIELAB s ystem, from the perspective of the typical threshold discrimination of the human eye. Color differences between neutralized and non-neutrali zed solutions occurred in;an appropriate direction of the color space to enhance discrimination and were clearly perceptible by normal obser vers (greater than 9.7 +/- 1.2 CIELAB units). Colorimetric analyses ha ve been used to draw conclusions regarding observers with defective co lor vision. The color of the solution changes abruptly, approximately 25 min after the neutralization process begins, and remains nearly con stant after about 60 min, this agreeing well with the temporal evoluti on of the hydrogen peroxide concentration.