Optical Problems and near Vision

Abstract

Optical problems related to near vision are caused by one of two factors. Some are related to the fact that near vision requires different accommodative effort than distance viewing. Other problems are related to the fact that near vision usually occurs in the downgaze reading position, and there are some clinical situations for which downgaze poses unique optical problems. This report presents ten specific optical problems associated with near vision. They include: 1) increased accommodative demands in myopes switching to contact lenses; 2) problems with bifocal contact lenses with high AC/A esotropia; 3) decompensation of accommodative esotropia with approaching presybopia; 4) the need for on-going cycloplegic refractions in former accommodative esotropes; 5) problems with monovision; 6) fixation switch diplopia/asthenopia; 7) monocular aphakia; 8) induced prism in downgaze from anisometropia; 9) vertically incomitant strabismus causing problems in presbyopes; 10) disadvantages of no-line bifocals with vertically incomitant strabismus.

• optical problems
• diplopia
• near vision
• prisms