Perhaps blindness is the most painful thing to happen to humans or animals. Being unable to see the people who love you adds to the pain and fear of the darkness. Pinnochio the little kitten was afraid of the dark and was suffering an eye infection during his younger years.
In a few months, he had an eye surgery and had finally made a full recovery. The physical body balances itself out in both humans and animals, so Pinnochio, whilst being blind, could have fun playing with other cats with an enhanced sensitivity in his hearing and feeling. This is just beautiful.