An extension of an accommodation and convergence model of emmetropization to include the effects of illumination intensity

The Flitcroft (1998) emmetropization model incorporates a classical model of accommodation and convergence with blur-driven feedback control of eye growth. We have modified this model by incorporating the effects of illumination (with or without extensive near work) on accommodation, vergence, pupil diameter and emmetropization. In addition to replicating Flitcroft's results, we show that (1) decreased illumination and (2) a low convergence accommodation/convergence (CAC) ratio exacerbate the progression of near-work-induced myopia. Our model further indicates that prescription of negative lenses, under these conditions, augments the advancement of myopia. (C) 1999 The College of Optometrists. Published by Elsevier Science Ltd. All rights reserved.