I have a dog who has one blue eye and one brown eye. Everywhere we go people comment on her eyes and are baffled by the fact they are different colours. In fact, most people think that there's something wrong with her sight, when that's not true at all. People assume that they must be blind in their blue eye when this is normally not the case.
So for all those people that aren't sure about dogs with different coloured eyes, here is a simple explanation of why it occurs. I personally think dogs with unusual eyes are interesting and stunning to look at. I still occasionally catch a glimpse of my dog's eyes and am blown away by how fascinating they are.
Unfortunately dogs in rescue centres with different coloured eyes tend to struggle to find a home compared to dogs with the same colour eyes. People often don't want a dog with so called defects such as this.
My dog is a rescue dog and thankfully she didn't struggle to get a home because we found her two weeks after she arrived at the rescue centre, but sadly that's not the case for some dogs that take months and months to find a home. For example, Molly at The Dog's Trust was much harder to rehome than her identical sister, the only difference was her sister has brown eyes and she has one blue and one brown (see more info on this story).
This condition is known as heterochromia, where the blue eye has less pigment than normal in it. Heterochromia simply means two different colours. Dogs with different coloured eyes are completely normal and happy. So if your dog has this then embrace it and be proud of having a unique dog. Don't worry about what other people think and correct them if they suggest your dog has sight problems.
This condition is also present in some other pets such as horses and cats. Humans can also have it although it is a bit more unusual. Famous actors such as Kiefer Sutherland, Kate Bosworth and Mila Kunis has one eye that is a slightly different colour. However, they have partial heterochromia (where only part of one eye is a slightly different shade) whereas a lot of dogs will have full heterochromia. There are a few breeds that are more susceptible to heterochromia such as Border Collies, Siberian Huskies and Australian Sheepdogs.
It's always worth getting your dog's eyes checked by a vet to check for any underlying conditions that you might be aware of. You can also test your dog's eyesight by getting someone to cover one eye and dropping a ball in front of them. If their eye moves to look at the ball as it drops then their sight should be OK, do the same with the other eye as they could have a problem with just one eye. Again, if you suspect anything it's definitely worth getting a professional opinion from the vet.