Nuclear Sclerosis in Dogs – Causes, Symptoms, and Treatment

nuclear sclerosis in dogs

Welcome to our guide to nuclear sclerosis in dogs! We will cover causes, treatment options, and much more in the guide below. It seems as though our furry friends age in the blink of an eye. Dog years pass so quickly, leaving our pups with a short lifespan and a number of potential age-related health concerns.

One common health problem for older dogs is nuclear sclerosis (otherwise known as lenticular sclerosis). Nuclear sclerosis in dogs is frequently observed in older dogs, typically starting at 7 to 9 years of age.

What is Nuclear Sclerosis in Dogs?

Nuclear sclerosis is the formal medical term for the bluish “haze” that forms in the eyes of older dogs. Nuclear sclerosis typically appears in middle-aged and senior dogs. It will manifest as a cloudy, often blue-tinted haze in the lens of the eye. It usually affects both eyes, and can progress quickly.

Although the name sounds intimidating, nuclear or lenticular sclerosis in dogs is not a serious health concern. With that said, it’s still important to be aware of the condition, and veterinary care may be required.

Nuclear Sclerosis Symptoms & When to Seek Help

The symptoms of nuclear sclerosis in dogs can include:

  • Hazy/cloudy eyes
  • A blue or grey tint in one or both eyes

The haze is often more apparent when viewed from the side, rather than directly. Nuclear sclerosis does not typically cause significant changes in vision, so it’s not considered a serious canine health concern. If you notice warning signs, it’s a good idea to talk with your vet. While nuclear sclerosis is not a serious concern, it’s good to rule out any other conditions that could be causing similar symptoms.

Causes of Nuclear Sclerosis in Dogs

The exact causes of nuclear sclerosis in canines are not fully understood.It is thought that the lens of the eye tends to harden with age. As new lens fibers are produced throughout the dog’s life, they put pressure on the central lens. This can cause a hardening of the lens tissue, and a discoloration/opacification of the eye.

Nuclear sclerosis appears to be a natural result of the aging process for most dogs. It affects the vast majority of older dogs – with some estimates putting the numbers as high as 50% for dogs over 9 and 100% for dogs over 13.


To diagnose nuclear sclerosis, a veterinarian will typically dilate the dog’s pupils for easy viewing. The eye will then be examined with an ophthalmoscope or other examination tool. Since nuclear sclerosis is so common in dogs, many vets will be able to easily diagnose the condition.

Treatment Options for Nuclear Sclerosis in Dogs

No specific treatment option is standard practice for this condition. In fact, no treatment is typically necessary – unless the condition leads to cataracts or other more serious concerns. With that said, dogs with nuclear sclerosis should be observed carefully to watch for signs of cataracts. The two conditions appear to be related, although nuclear sclerosis is not thought to directly cause cataracts.

Nuclear sclerosis doesn’t significantly affect vision in dogs – but cataracts can. Thus, pet parents of a dog with nuclear sclerosis should plan regular checkups at a licensed veterinarian.

Cataracts vs Nuclear Sclerosis in Dogs

Nuclear sclerosis and cataracts are two very different conditions – but to the untrained eye, they can appear quite similar. Nuclear sclerosis does not usually affect vision or damage the eye significantly. Cataracts, on the other hand, can cause significant vision changes and other serious symptoms.

Since both conditions are characterized by an opaque, cloudy appearance in the eye, it can be difficult to tell the difference between nuclear sclerosis and cataracts. To diagnose the correct condition, a licensed veterinarian will perform an ophthalmologic exam, looking closely at the dog’s corneas, retinas, and eye tissue.


The outlook for a dog diagnosed with nuclear sclerosis is overall quite good. The condition does not usually cause any significant changes in vision, nor does it cause discomfort for your dog. However, nuclear sclerosis typically appears after the age of 7 or 8, when many dogs start to develop other eye health concerns. For many, nuclear sclerosis can be a type of warning sign that it’s time to start paying closer attention to any changes in your dog’s behavior or appearance.


Nuclear sclerosis results from natural changes to your dog’s eyes associated with aging. There are no preventative steps to take to prevent the condition. However, regular health checkups should be scheduled throughout your dog’s life to monitor overall health and keep a close eye on developing concerns.

Eye exams should be included as part of a regular veterinary check-up. However, some vets won’t pay much attention to a dog’s eyes until the later years. If this is the case with your vet, it’s worth asking for a quick eye exam to be attached to your dog’s regular health check-ups.

The Labrador Handbook by Pippa Mattinson

nuclear sclerosis in dogs


Nuclear sclerosis in dogs is an extremely common condition, and typically is not cause for worry. It is a purely cosmetic condition, which does not cause any discomfort for your dog, and does not cause significant changes in vision. Veterinary visits should still be scheduled when your dog begins showing signs of the condition – primarily to check for signs of cataracts and other more serious concerns.

References and Further Reading

The Labrador Site Founder

Pippa Mattinson is the best selling author of The Happy Puppy Handbook, the Labrador Handbook, Choosing The Perfect Puppy, and Total Recall.

She is also the founder of the Gundog Trust and the Dogsnet Online Training Program 

Pippa's online training courses were launched in 2019 and you can find the latest course dates on the Dogsnet website


  1. Hello

    My 11month male maltese pup isn’t even a year and yet has this gry/white pupil in his left eye. He’s suppose to be a 4-5 pound maltese yet weight 16.04 pound which is alot he’s huge and heavy. His parents are small and had pups that came out small. He was the only huge baby pup. He’s not a middle age dog to have sclerosis / cataract or any other problem. Yet his eye looks weird it glows yet. His other eye looks fine until I take him in.

  2. My 11 year old Lab was diagnosed with Nuclear Sclerosis. He is doing really well. I noticed that he does fine during the day time but in the evenings is when he doesn’t see very well. I just keep a close watch on him and we go for our routine physical check up every year and we have his eyes checked as well.

    • Re-read the article. The part – researched by experts, not anecdotal evidence – that says very specifically:
      “It is a purely cosmetic condition, which does not cause any discomfort for your dog, and does not cause significant changes in vision.”