The effect of target proximity on the aniso‐accommodative response

Aniso‐accommodation (unequal binocular accommodation) to lens‐induced anisometropia has been demonstrated by subjective and objective measurement techniques (Marran and Schor,Vision Res.38(22), 3601–3619). The gain of the response was significantly reduced for some subjects when aniso‐accommodation was stimulated by a target at 1 m compared to a target at 20 cm, even when the targets viewed were matched in retinal image size, convergence levels andaniso‐accommodative stimuli. The two conditions did differ in both the accommodative level and proximity of the target. Thus the higher gain of the response in the 20 cm condition could have arisen from either high proximity, high accommodative level or a combination of both.