A person came to eye OPD for routine eye check. On snellen's cha he was found to read 6/6 in both eyes. What is the largest approximate distance at which he would be able to read the first topmost letter
What does 6/6 mean in Snellen's cha * It means that the patient with or without glasses can see the letter at a distance of 6 m which a person normally should have been seeing at 6 m Now you would understand it by next example * 6/12 means a letter which a normal patient should be seeing at 12 metre , this patient can see only when he is nearer, that means 6 metre from Target * 6/60 means that a normal patient should be seeing at 60 metre, but this patient has to be much closer that means 6 metre * This also means that the letter written at 6/60 is big enough that 6/6 vision person can read it at even 60 metre
36 m
24 m
60 m
1 m
Optics and Errors of Refraction