What this means
It helps to notice which part of the eye looks cloudy. A bluish, film-like haze on the surface points to one area, while a white or grey patch deeper behind the pupil points to another. In older dogs the lens can turn greyish, and that does not always mean loss of sight, but it cannot be known without an examination.
What matters most is whether it appeared suddenly or gradually, and whether the eye looks painful. A sudden change, redness, squinting, watering or a widened pupil means you should go the same day.
Note down whether your dog has begun bumping into things, avoids stairs, does not want to go out in the dark or seems unsure in a new place. Such changes can hint at weakening sight before the eye itself looks different.
Possible causes
These are things that can cause this sign. It is not a diagnosis, and they are not equally likely for your dog.
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Clouding of the lens
The lens can turn cloudy and the eye looks grey or whitish. It happens in older dogs, and in some breeds at a younger age.
About the condition: Cataracts -
Raised pressure in the eye
When the pressure in the eye rises, the clear front of the eye turns bluish and cloudy, and the eye is red and painful. This is an emergency.
About the condition: Glaucoma -
Changes in the cornea
Damage to the surface of the cornea, inflammation or fatty deposits cause clouding at the front of the eye.
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A displaced lens
When the lens slips out of its usual place, the eye may look cloudy, red and painful. Some breeds are prone to this.
About the condition: Primary lens luxation -
Age-related hardening of the lens
In older dogs the lens may turn grey and look cloudy even though sight is still largely good. Only an examination can tell the two apart.
What else to watch for
These observations help your vet build the picture faster. Note down what you saw and when.
- Whether the cloudiness appeared suddenly or gradually
- Whether one eye or both
- Whether the eye is red, watering or squinted
- Whether your dog bumps into things or avoids stairs
- Whether both pupils are the same size
- Whether behaviour changes in the dark
When to book a routine visit
Book a visit if you notice cloudiness, even without pain, because an early examination helps find the cause. If the eye looks painful or red, go the same day.
Related conditions
Conditions whose entries mention this sign. The list is somewhere to read on, not a way to reach a diagnosis.
- Cataracts Eyes A cataract is a clouding of the lens of the eye, in which the clear lens turns milky or pearly and lets less and less light through to the retina. It can be inherited and appear in a young dog, develop with age, or come with other diseases such as diabetes. The clouding may stay small or spread until the dog can no longer see, so the eyes should be checked by a vet.
- Glaucoma Eyes Glaucoma is a condition in which the pressure inside the eye rises because fluid can no longer drain out of the eye as it should. The raised pressure presses on the retina and the optic nerve, so glaucoma is very painful and can quickly take away sight. It is an emergency: the dog needs a vet immediately.
- Corneal dystrophy Eyes Corneal dystrophy is an inherited condition in which fat or mineral deposits build up in the clear cornea of the eye, or its cells stop working properly, so the cornea becomes cloudy in places. It can be entirely painless and affect vision little, but some forms can cause the cornea to swell or develop small ulcers. A vet assesses the changes and follows how they develop.
- Primary lens luxation Eyes This is an inherited eye disease in which the fine fibres that hold the lens in place weaken, so the lens shifts or comes loose entirely. If the lens slips into the front of the eye, it can block the drainage of fluid and cause a sudden rise in eye pressure, which is very painful and threatens sight. In that case the dog needs a vet immediately.
Body systems: Eyes