Comparing the Snellen and the Catford Visual Acuity Test

Supa Kongsaengchai Bsc.,
Prut Hanutsaha M.D.
Department of Ophthalmology, Ramathibodi Hospital, Faculty of Medicine, Mahidol University

ABSTRACT A prospective study comparing the Snellen and Catford visual acuity measurement was performed in 100 subjects (200 eyes), 30 males and 70 females age 15 – 76 years. There is good correlation between the two measuring methods, with the correlation coefficient (r) = 0.7209. Nearly 20 percent of the eyes had different visual acuity results between the two methods. Most of them (18 %) had the better visual acuity by Catford visual acuity test.

Thai J Ophthalmol 1991; Jan – June 5 (1) : 1-5