Piggy-back fitting of contact lenses.
D000293:Adolescent; D000328:Adult; D000368:Aged; D001251:Astigmatism / Q000209:etiology / Q000628:therapy; D003261:Contact Lenses / Q000592:standards*; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D009885:Ophthalmology / Q000379:methods*