Preferential Looking in the Mentally Handicapped

We have assessed the feasibility of Preferential Looking (PL), using Teller Acuity Cards, for the estimation of binocular and monocular visual acuities in a group of mentally handicapped adults. Our results show the comparison between grating and recognition acuities, inter-observer variation, success rate, time taken and the sensi­ tivity of this method in identifying monocular visual deficit in this group of subjects. The reasons for success or failure with PL methods in relation to criteria for mental handicap are discussed.