Pattern-reversal electroretinograms(P-ERG)and visual evoked potential(P-VEP) were simultaneously recorded in 20 kittens reared with unilateral convergent strabismus,induced surgically at around 3 weeks after birth.P-VEP responses evoked through the normal and squint eyes consisted of two components at the initial stages,however changed systematically with age,and the second component of the squint eye disappesred earlier than that of the normal eye.P-ERG response for the variance in retinal function of squint eyes was more sensitive than the F-ERG.P-VEP responses from the squint eyes reduced significantly in amplitude as compared with those evoked through the normal eyes,even one week after surgery,while P-ERG responses unchanged and persisted through 30 weeks.Reduction of P-ERG amplitude of squint eyes developed about 6 weeks postnatal and the spatial resolution returned gradually at later stages.The results suggest that the strabismus may affect not only striate cortex,but also retina in developing kittens.In comparison with retinal deficits,cortical deficits may arise earlier and manifest more severe.