The role of the limbal cornea in vision

The eagle retina is bifoveal. The temporal fovea, which can resolve targets subtending half a minute or less must depend upon its peripheral cornea for such sharp resolution. Our studies showed the eagle cornea to be thinner, scatter less light and be more spherical than the human cornea. Further experimental studies determined the resolving power of the human peripheral cornea. Using, normal subjects, pinholes placed at the edge 8 mm dilated pupils yielded 20/30 visual acuity and normal contrast sensitivity measurements. Thus it is recommended that optical iridectomy be considered, in appropriate cases of corneal blindness with patches of clear peripheral cornea when no donor corneal material is available.