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Why Does My Cat Have Round Pupils All the Time?

Why Does My Cat Have Round Pupils All the Time?

Is it normal for pupils to dilate and constrict constantly? We widen the black part in the center of our eyes so that we can see better. In this case, animals also function in the same way. Dilated pupils enable us to absorb more light and enhance our vision, especially in the dark. 

However, a cat has round pupils when excited, surprised, frightened, or hurt. Fortunately, it is not a matter of concern since the dilation usually goes away on its own. But what if your cats’ pupils are dilated all the time? Well, this may indicate potential danger to your cat’s eyesight. 

Prolonged dilation of pupils, high blood pressure, and hypertension are the most common causes of concern in most cats. It can also indicate chronic disorders, feline leukemia, brain tumors, heart disease, loss of vision, anxiety, and several other conditions.

So, if your cat has round pupils all the time, you should certainly consult a healthcare professional.

Why Do My Cat’s Eyes Dilate?


Cats have dilated pupils at night to absorb more light and see clearly. They see best when there is more light entering their pupils. If the light is not dim, pupil dilation may indicate something else.

It may be because of pain, sickness, or eye trauma. Some other reasons include: 

  • Loss of vision 
  • Hypertension 
  • Ocular tumors
  • Chronic pain
  • Anxiety 
  • Feline Dysautonomia 
  • Iris Atrophy 
  • Overstimulation 

1. Loss of Vision 

If your cat is experiencing poor eyesight, it suggests their eyes will stay dilated all the time to absorb as much light as possible. As cats age, they are more likely to lose their vision. Besides having round pupils constantly, your cat may be acting clumsy and bumping into objects now and then. 

In such cases, your cat may also be cautious while climbing, walking, and jumping. A cat may be going blind when they startle at sudden noises and grow frustrated if you do not respond quickly. The reason for poor eyesight may not be apparent. However, it could be a symptom of underlying kidney disease or eye infections.

If you suspect your cat is going blind, you should visit the vet as soon as possible. You can also test your cat’s eyesight at home, but it is recommended that you consult a veterinarian.

If you find out your cat is losing its vision, do not panic. Instead, make some adjustments to accommodate your pet. Cats primarily rely on their sense of smell and touch, so they will soon adjust to poor vision.

White kitten

2. Hypertension 

Hypertension is a widespread cause of constantly dilated and round pupils in cats. Older and significantly obese cats develop a greater risk of high blood pressure.

If you notice the following symptoms, take your cat to the vet for a proper diagnosis. 

  • Blood in urine 
  • Irregular heartbeat 
  • Seizures 
  • Excessive water consumption 
  • Nose bleeding 

The treatment varies depending on the reason behind hypertension. Cardiac diseases or kidney failure can cause hypertension, but there may be no definite cause of hypertension in cats in some cases.

However, do not worry if you regularly take your cat to the vet and follow the guidelines provided by the vet.

3. Ocular Tumors

If your cat cannot constrict their eyes, there may be tumors behind the eyes. Often, it is a malignant tumor that spreads throughout the body of your cat. Malignant tumors can be extremely painful for cats and cause cloudy eyes, discoloration, inflammation, and discharge from the eyes. Moreover, glaucoma and mishappen iris are also common in cats suffering from malignant tumors and cancer. 

It is best to get the tumor removed from the body as soon as possible. If the cancer is significantly smaller, it can be treated with a laser. However, if the cancer worsens, the veterinarian may have to remove your cat’s eye. Do not worry; your cat can adjust to living with a single eye. 

4. Chronic Pain

Most of the time, cats have round pupils when in pain. A unique thing about cats is that they tend to hide their pain because they think it makes them vulnerable to predators. As a result, constantly dilated pupils are the only visible symptom of chronic pain. 

Alongside round pupils, a cat may also be lethargic all the time. In addition to this, you may notice a loss of appetite or excessive aggression in your cat. If your cat is uncomfortable, they will refuse any cuddling or petting.

To pinpoint the reason for the pain, it is best to take a trip to the vet. Only professional healthcare can diagnose the reason behind chronic pain. Follow their advice if you want to make your cat feel better. You can also use soft blankets, nutritional supplements, and regular massages. 

Meowing cat

5. Anxiety 

Following the list, another reason cats have wide eyes is fear and anxiety. If your cat is frightened or anxious, you need to determine the trigger. A lot of stress can trigger anxiety in your cat, meaning they will always be on edge. 

Your cat may startle at sudden loud noises or in the presence of an animal. When you figure out why your cat is startled, make adjustments to have them feel more comfortable.

Final Thoughts 

Cats are creatures with expressive eyes. The dilation and constriction of a cat’s eyes in different situations is entirely normal. However, if your cat frequently has round pupils, it is a matter of concern. 

This article listed some of the reasons why your cat may have round pupils all the time. Nevertheless, do not substitute this article with a piece of professional advice. If you notice a change in your cat’s eyes, it is best to seek the advice of a veterinarian. 

In mild cases, you may only need to make a single visit to the vet. Further, the doctor may recommend some noticeable adjustments to your cat’s lifestyle to keep them calm.