Lid suture myopia in chicks.

Domestic chicks reared under continuous light developed light-induced avian glaucoma (LIAG), including eye enlargement and flat cornea. Chicks reared under dim light developed dim light buphthalmos (DLB), a somewhat similar eye enlargement, superimposed on the LIAG effect when, as in one subgroup of the present experiments, the dim light was also continuous. Unilateral lid suture elicited experimental myopia on the operated side, additive to the LIAG and/or DLB effects. When the rearing conditions were diurnal (ie, not such as to induce LIAG eye enlargement), and the light of at least "normal" brightness, lid suture still caused unilateral myopia, accompanied by a pronounced bulging of the cornea. We discuss the probable effects of these changes on refraction and accommodation during the chick's development.