"Fleischer ring" is a distinct feature of

A condition in which the clear tissue on the front of the eye (cornea) bulges outward. Visual: astigmatism, blurred vision, distoed vision, double vision, inability to see in dim light, nearsightedness, sensitivity to light, or vision loss Also common: a rim of discolouration around the front of the eye (fleischer ring) Picture show Keratoconus, a non circular, non-centered oval caused by a bulging cornea. Very common in Keratoconus, it is best viewed under cobalt blue light, that's why the sclera looks blue. Reference: Ganong&;s review of medical physiology 25edition page 132