The Arden grating test of visual function: a preliminary study of its practicability and application in a rural community in north-west Iran.

In a preliminary study involving 75 normal and 10 abnormal eyes the Arden grating acuity test was assessed under difficult conditions of rural field work. It was found to be adequately sensitive and specific for screening out individuals with visual impairment due to refractive errors or ocular disease, and to distinguish between these. Inexperienced paramedical personnel could carry out the test satisfactorily with no difficulty and with a minimum of training. In spite of the unusually distracting conditions under which the test was carried out 95% of the subjects tested performed satisfactorily. The results of this preliminary study suggest that the Arden grating test is a valuable tool for screening large populations in rural areas of developing countries.