To investigate of visual field and contrast sensitivity abnormalities frequency in boys deaf high schools students of Tehran

Sixty four eyes were tested for visual fields and contrast sensitivity. They all have intelligence quotient (IQ) more than 70. We investigated their visual fields to measure foveal threshold, mean deviation, PSD and range of glaucoma hemifield test by using Humphrey automated perimeter and contrast sensitivity by using Vector vision CVS-1000 in 4 different spatial frequencies.

The results demonstrated that Profound hearing loss was noted in 50% of them and frequency of abnormalities in visual field test were from 31.02% to 60.09%.Frequency of early defect was 26.6% which was the largest frequency of visual field defect in deaf students.Frequency of Contrast sensitivity abnormalities in 4 different spatial frequencies was from 51.6% to 65.6%.The largest abnormalities was at 18cycles per degree.

The larger frequency of foveal threshold defects in children with hearing loss than the other visual field defects and also the larger frequency of contrast sensitivity abnormalities in high spatial frequencies than the other frequencies may demonstrate more defects in the center of visual system comparing with its periphery in indivitioal with hearing loss. We 133 conculoded that a deaf boy is at greater risk of visual filed and contrast sensitivity abnormalities than hearing boys.