A dog with one blue eye and one brown eye can attract immediate attention. The term for different iris colours is heterochromia. It describes an appearance; by itself, it does not tell you how well the dog sees or whether a recent eye change is harmless.
The American Kennel Club’s Australian Shepherd overview notes that the breed can have two differently coloured eyes or more than one colour within an eye. A familiar, longstanding feature is a different observation from a colour change you have just noticed.
Describe the part of the eye you mean
The iris is the coloured area around the pupil. A different-sized pupil, a cloudy surface, redness or a change in reflected light should not all be grouped under “different eye colours.” Precise descriptions help a veterinarian understand what prompted your concern.
For example, VCA’s veterinary explanation of anisocoria concerns unequal pupil sizes, not heterochromia. It also describes associated signs that may require assessment, including discomfort, cloudiness and discharge. A new abnormal eye appearance deserves prompt veterinary advice.
Use photographs as a record, not a diagnosis
If the dog is comfortable, an ordinary photograph in soft light can help document the change. Compare it with older pictures taken in similar conditions. Flash, reflections and exposure can alter how eyes look, so a photograph cannot replace an examination.
Note when you first noticed the difference and whether the dog is squinting, rubbing the eye, avoiding light or behaving differently. Avoid repeatedly shining a bright light into the eyes to test them.
Leave treatment to the examination
Do not use leftover eye drops or a product prescribed for another animal. Different eye problems can require different treatment, and a colour description is not enough to choose one.
If the two colours have always been present and the dog has no concerning signs, you can still mention the feature at a routine veterinary visit. The clinician can place it in the dog’s individual history.
Enjoy the distinctive appearance, while keeping the vocabulary accurate: heterochromia names the colour pattern, and an eye examination answers the health questions.