S.no   Chart tests MC Michelson Contrast Letter Letter luminance cd/m2 Background luminance cd/m2 Test simulates 1 ETDRS 97% 97% Black 1.6 100 Mesopic–high contrast 2 ETDRS 25% 25% Grey 8.5 5.1 Mesopic–restaurant 3 ETDRS 50% 50% Grey 1.6 4.8 Mesopic–driving at dusk 4 ETDRS 10% 10% Grey 81 100 Photopic–sun overhead 5 ETDRS 8% 8% Grey 85 100 Photopic–sun 15° off-axis

Tables 1b: ETDRS chart testing is presented with the letter and background luminance for each test. MC=Michelson Contrast, cd/m2=Candelas per meter squared.