Detect The Effects Of Age On The Time Threshold Of Visual Acuity

Obstract: Controlled by a computer ,to study the effects of age on the time threshold of visual acuity.Methods: The optotypes are programmed in pascal. The size ,the programe and the lasting time of the optotypes are controlled by a computer. The subject looked at an optotype on the distant of 5 m. The time threshold of visual acuity is detected with the stairecase method. The light threshold and contrast threshold are detected with the limits method.Results:Time threshold of visual acuity in normal children is about 88.70msec,in normal young men is about 27.90msec,in normal old men is about 72.40msec.The light threshold in normal young men is about 0.30%,in normal old men is about 4.2%. The contrast threshold in normal young men is about 25.10%,in normal old men is about 40.60%.Conclusion: From the research results above,we can draw a conclusion that the time threshold of visual acuity, the contrast threshold and the light threshold are related with the age . Using a computer, we can detect the time threshold of visual acuity and contrast threshold well,but we can not detect light threshold.