Question

what is meaning of 'human eyesight 6/9 corrected to 6/6'?

Answer 1

The test is for checking distant vision. The chart used is called Snellen chart. Basically, the letters on the chart are read from a distance of 6 metres so that explains one 6. The other number says till which line you are able to read. 6/6 is the last line with the smallest letters. So when you are reading your vision is 6/9 indicating some amount of far-sightedness. They prescribe glasses to correct your eyesight and to get your vision to 6/6