Central circular clouding.
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D003261:Contact Lenses / Q000009:adverse effects*; D003315:Cornea / Q000033:anatomy & histology; D003318:Corneal Opacity / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged