H.P. Derksen

Het Loo-Erf,
Waldeck Pyrmontstraat 31,
NL 7315 JH Apeldoorn,
The Netherlands

In this pilot I looked at the contrast sensitivity and a possible relationship in using or advising telescope systems.

In most cases it will be impossible to give a visual impaired person advice on his optimal visual environment, based on the ophthalmological diagnosis alone. Various parameters of vision are possible to help the clinician for a visual assessment.

I choose for contrast-sensitivity and visual acuity related to prescribe a telescoopsystem.

A total group of 137 visual impaired persons, man and woman, were tested during a period of 1 year at the Loo Erf institute using there telescoopsystems.

One group n=82 use there telescoopsystems over a longer time period, and the second group n=55 where having there telescoopsystem for the first time, after measuring the contrast sensitivity and visual acuity.

The results show that there are more subjects having problems in using their telescoopsystems when they have a low contrast sensitivity, low spatial frequency (p£ 0.02) than they who’ll have a contrast sensitivity in the mid or high spatial frequencies.