Are 6-6 in both eyes are good or bad?

Answer 1

6/6 vision means you are seeing a size 6 letter at 6m away.

This is considered good vision, the equivalent of the American 20/20 vision (they use feet, instead of metres, 6m = 20ft)

The first number donates the testing distance, while the second number donates the size of the letter you can see at that distance.

If the first number stays the same, the larger the second number, the poorer your vision. For example, the number plate test you are given before a driving test is roughly equivalent to 6/10. Around 3/36 or worse (while fully corrected) can be classed as a visual impairment.