<prompt> Fleischer ring is a distinct feature ofKeratoconusPterygiumCongenital ocular melanosisCongenital epithelial Melanosis  <response>: 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, thats why the sclera looks blue. Reference: Ganong;s review of medical physiology 25edition page 132 