No, I can't touch up photos in Photoshop and so haven't changed the color of one of the eyes of the cat in the photo above. I came across this cat at Matharpacady at Mazgaon in Bombay with each eye of a different color and took this photo with my friend Mark's digital SLR. Having seen many cats with differently colored eyes and wondering the scientific reason behind this, I looked it up and found the following...
This condition is called "Heterochromia" and is used to describe a multi-colored iris within the same eye, or two eyes with distinctly different colored irises. This is commonly seen in cats, horses and some breeds of dogs but is rare in humans. In this condition, the vision is completely normal and heterochromia is not considered a medical problem.
Heterochromia in humans can be hereditary, caused by a disease or syndrome, or due to an injury. According to Wikipedia, notable celebs having heterocromia are David Bowie, Christopher Walken, Dan Aykroyd, Jane Seymour, Mila Kunis, and Kate Bosworth. For more information on heterochromia look up Wikipedia here.
The first time I saw a dog with such eyes was 7 years ago when I came across a female stray dog at Kemps Corner and took it for sterilization. Her one eye was blue and the other one was brown. She was really very sweet and readily came with me wagging her fantail. After we left her back I used to see her all over, sometimes on Hughes Road or at Walkeshwar or on Peddar Road and at her original location. She was quite a wanderer and the only way I used to recognize her was because of her eyes. Unfortunately, she passed away last week.