Cataracts

Cataract vs nuclear sclerosis

The gray-blue haze most senior dogs develop is usually nuclear (lenticular) sclerosis — a normal aging change that does not meaningfully impair vision. A true cataract looks white or opaque and blocks the tapetal reflection. A vet exam distinguishes the two in about 30 seconds.

Common causes

• Diabetes mellitus (most diabetic dogs develop cataracts within 12 months)
• Inherited/breed-linked in Cocker Spaniels, Poodles, Boston Terriers, Siberian Huskies
• Trauma or intraocular inflammation
• Age-related (senile cataracts)
• Nutritional (rare, mainly in orphan puppies on inadequate replacer)

Treatment

There is no drop, supplement, or diet that reverses a cataract. Surgical phacoemulsification by a veterinary ophthalmologist restores vision in the majority of appropriate candidates. Untreated mature cataracts can cause secondary glaucoma and lens-induced uveitis, both painful, so consult an ophthalmologist even if you decline surgery.

Why it matters

Owners often assume gray eyes = cataracts = blindness and delay diabetes screening. In reality most senior gray eyes are harmless sclerosis, and true cataracts are worth diagnosing early because underlying diabetes is treatable and surgery is highly effective.