I believe it is to avoid soical problems and to prevent the spread of communicable diseases
It is use by Eye Care Professionals To check the eyesight of a person.
If u would have visited a eye care centre u would have noticed a chart like this--
If a person can see all the letters from a distance his eyesight is Perfect.If that person misses a letter or a line from the grid eye treatment or spectacles are given to the person for improving their eyesight
I would feel , a little bit sad but then I’ll get over it and begin with my life
Yes, it can with excercise. The more you exercise the stronger it will become