A laser accident patient's parafoveal visual field defect was modeled
and his performance on a tank recognition task was compared with that
of a participant in the modeled scotoma condition and in two central s
cotoma conditions. The modeled parafoveal scotoma, and foveal and macu
lar occluding scotomas were stabilized on the retina using a dual Purk
inje Eye-Tracker and a multiplane digital image display. The simulated
scotomas suppressed military target recognition functions in a manner
consistent with previous studies. Neither central nor parafoveal scot
omas were sufficient to reduce sensitivity to the patient's level. How
ever, when the foveal and parafoveal scotoma functions were combined t
o account for the patient's macular damage, prediction for patient per
formance significantly improved. The data suggest that models of retin
al damage from laser exposure must include not only visual field defic
its but also deficits in high (visual acuity) and low spatial frequenc
y visual function.