An evaluation of visual acuity with the Corning CPF 527 lens

The effect of visual acuity on the Corning 527 photochromatic lens was studied for a group of 50 normal patients and 53 low vision patients. Visual acuity was measured at 10 feet using three Lighthouse Low Vision Distance Acuity Charts, whose letters were randomly arranged. Acuity measurements were performed under three conditions: through a plano lens, a Corning 527 lens and an equivalent neutral density filter, each placed over the best corrective lenses. No statistically significant difference in acuity measurements were found between these three conditions.