The Ability to Perceive a Minor Change in Luminosity Lab Report

The Ability to Perceive a Minor Change in Luminosity - Lab Report poserTo perform the CS test (CST), the basic necessitys for all four tests were 1) to have an adequate luminance level required for each test 2) to have meticulous test outstrip and 3) to perform each test approximately at the same kernel sight level as that of test charts. The CST luminance requirement for Pelli-Robson charts was 60120 cd/m2, while for Vistech6000 and Cambridge plates the adequate luminance levels were 103240 cd/m2 and 100 cd/m2 respectively. The Lux value required for Cardiff cards CST was equal to that of the hoary background cards. For each test the required Lux level was verified by using a Lux meter. The value of precise test distance varies from test to test. For Pelli-Robson CST the required separation was 1 m. For Vistech and Cambridge plates CSTs, the required separation was 3.048 m and 6 m respectively, and within the acuity limit for Cardiff cards CST (Wood and Wood 1995). later havi ng all basic requirements for each test, the test charts/cards were hung vertically on a wall one after the other. To determine CS values, corresponding observations were make first with the unspoilt meat (without any correction), starting horizontally on each line of charts/cards and moving from the left hand side to the right hand side, and then from top to bottom for each letter/symbol on the chart /card. The tests were repeated for a plastic in front of an eye pretended to be a cataract. The tests were concluded when two or three letters/symbols were named incorrectly. The corresponding observations for CS were recorded. The CS function (CSF) value obtained for monocular right eye (RE) testing without cataract through Pelli-Robson CST is 1.95 while with cataract it is 1.65 a quite lower value (fig. 4 and 5) . From Cardiff CST the evaluated contrast (%) values for monocular.