Prescribing for presbyopes who use VDUs.
It has been widely assumed that VDU users position their paperwork closer than the screen to their eyes by an amount which may exceed their depth of field. The design and prescription of spectacles for the presbyopic VDU user must take these working distances into account. From theoretical considerations, the focal characteristics of occupational spectacles are matched to combinations of working distances. Measurement of these distances was carried out on a sample of 243 VDU users, 101 of whom were presbyopic and 53 nearing presbyopia. The results were analysed in terms of type of work and accommodative reserve, and compared with previous studies. Contrary to the views of several previous workers, it was found that paperwork did not tend to be positioned closer than the screen to the eyes. This finding was little affected by the type of VDU use or the accommodative reserve of the subject. Special occupational spectacle lens forms are thus not generally indicated for presbyopes at the VDU workstation.
Burns
D
D
Department of Optometry, City University, London, UK.
Obstfeld
H
H
Saunders
J
J
D000065:Accommodation, Ocular / Q000502:physiology; D016288:Computer Terminals; D003626:Data Display; D004215:Distance Perception / Q000502:physiology; D005139:Eyeglasses; D006801:Humans; D055095:Optics and Photonics; D011305:Presbyopia / Q000628:therapy*