Question: why each eye is tested separately?
Answer: EXPLAIN WHY EACH EYE IS TESTED SEPARATELY WHEN USING THE SNELLEN EYE CHART? BECAUSE BOTH EYES COULD HAVE DIFFERENT VISION, COMPAIRED THE OTHER VISION IS NOT THE SAME. PERSON CAN SEE AT 20 FT WHAT A PERSON WITH NORMAL VISION CAN SEE AT 10 FT. BETTER THEN NORMAL VISION.