Aspheric contact lenses used to control convergence excess

Abstract

A 15‐year‐old female patient presented wearing progressive addition spectacle lenses to help control a condition of convergence excess. She was fitted with aspheric, multifocal, rigid gas permeable contact lenses for cosmetic reasons. The lenses were fitted 1.5 dioptres steeper than the flatter keratometer reading, and incorporated an eccentricity value of 0.7. Visual acuities through these lenses were 6/7.5 at both distance and near in each eye. Phorias through the lenses were measured using two methods. The cover test revealed 1 D of esophoria at 6 m and 3 D of esophoria at 40 cm. The Maddox rod also yielded 3 D of esophoria at 40 cm. (Clin Exp Optom 1993; 76.4: 141–142)

Key words:

• aspheric contact lenses
• convergence excess