I am not completely sure on that but the pintos can have some interesting eye colors. The colt I know has absolutely no problem with his vision though. Hopefully someone can give some info on the subject.
Here is some funky color genetics I can try to tell you about. The colt I was talking about, Hellboy, is a solid sorrel with absolutely no white that we can see. His yearling sister is a sorrel and has white "birdcatcher" spots on her rump that magically appeared after clipping when she was about 5-6 months old and have been increasing ever since. She has brown eyes but She came to the stable when she was 2 month old so we do not know what her eyes looked like up close. I do have day old pictures of her and her eyes look dark brown. We have been trying to figure out what color and/or what their dna color is. The sire and dam are the same for both. The dam is a solid bay and the sire is a sorrel overo with blue eyes. The sire's sire is Sundance LB Brightly Attired, a loud black and white overo. I talked to their old owner and she thought that Hellboy might have the blueish eyes from his sire.
There is some food for thought. At this point we are quite confused with colors and genetics as I am sure you are, too.