Why can i see my Cat’s third Eyelid? 7 Key Reasons

Why can I see my Cat’s third Eyelid: 1. Sleepiness 2. Dehydration 3. Eye infection 4. Stress or fear 5. Digestive upset 6. Injury or trauma 7. Underlying illness.

Why can I see my Cat’s third Eyelid?

If you suddenly notice a pale or whitish film partially covering your cat’s eye, you are likely seeing the third eyelid, also called the nictitating membrane.

This can be alarming for cat owners, especially if it appears in one or both eyes. While the third eyelid normally stays hidden, its visibility often signals health, stress, or eye-related issues that should not be ignored.

Quick Overview: Common Reasons the Third Eyelid Shows

Cause	What Happens	Serious Level
Normal sleep or relaxation	Eyelid shows briefly	Low
Dehydration or illness	Eyelid stays visible	Medium
Eye infection	Redness and discharge	Medium
Digestive issues	Linked body stress	Medium
Neurological problems	Eye movement changes	High
Injury or trauma	Sudden appearance	High

What Is a Cat’s Third Eyelid?

The third eyelid is a thin membrane located at the inner corner of a cat’s eye. Its job is to:

• Protect the eye
• Keep the eye moist
• Remove debris

In healthy cats, it is usually not visible unless the cat is sleeping or very relaxed.

1. Your Cat Is Very Relaxed or Sleeping

It is normal to briefly see the third eyelid when a cat is:

• Falling asleep
• Waking up
• Deeply relaxed

In these cases, the eyelid disappears once the cat is fully alert. This is not a cause for concern.

2. Illness or General Weakness

When a cat feels unwell, the muscles that control the eyes can weaken. This causes the third eyelid to remain visible.

Common illnesses linked to this include:

• Viral infections
• Fever
• Digestive upset

If your cat seems tired, withdrawn, or off food, the visible eyelid may be a sign of underlying illness.

3. Dehydration

Dehydration reduces fluid pressure behind the eyes, making the third eyelid more noticeable.

Signs of dehydration include:

• Dry gums
• Lethargy
• Reduced appetite

Cats that eat only dry food or are sick are more prone to dehydration.

4. Eye Infections or Irritation

Eye infections can cause swelling and inflammation, pushing the third eyelid upward.

Look for:

• Red or swollen eyes
• Yellow or green discharge
• Squinting or pawing at the eye

Eye infections require veterinary treatment to prevent damage.

5. Digestive Problems (Haws Syndrome)

Sometimes the third eyelid appears due to digestive upset, even when the eyes themselves look normal. This condition is often called Haws syndrome.

It is commonly linked to:

• Diarrhea
• Parasites
• Sudden diet changes

This usually resolves once the digestive issue improves.

6. Injury or Trauma

Any injury to the head, face, or eye can cause the third eyelid to show.

Possible causes include:

• Scratches from other cats
• Foreign objects
• Accidental impact

Sudden appearance after trauma should always be treated as urgent.

7. Neurological or Systemic Conditions

In rare cases, nerve damage or systemic disease can affect eye muscles.

Warning signs include:

• Uneven pupils
• Head tilt
• Poor balance

These symptoms need immediate veterinary attention.

Normal vs Abnormal Third Eyelid Appearance

Feature	Normal	Concerning
Duration	Brief	Persistent
Eye discharge	None	Present
Behavior	Normal	Lethargic
Appetite	Normal	Reduced
Eye redness	None	Visible

When Should You See a Vet?

Contact a veterinarian if:

• The third eyelid stays visible for more than 24 hours
• Both eyes are affected
• There is discharge, redness, or pain
• Your cat acts sick or weak

Early treatment prevents long-term eye damage.

What You Should Not Do

• Do not use human eye drops
• Do not ignore persistent eyelid visibility
• Do not try to pull the eyelid back

Improper handling can worsen the condition.

FAQs

Q1: Is it normal to see a cat’s third eyelid sometimes?
Yes, briefly during sleep or relaxation is normal.

Q2: Can stress cause the third eyelid to show?
Yes, stress can weaken eye muscle control temporarily.

Q3: Does a visible third eyelid mean blindness?
No, it usually does not affect vision directly.

Q4: Can dehydration cause this problem?
Yes, dehydration is a common cause.

Q5: Should I clean my cat’s eye at home?
Only if advised by a vet and using approved solutions.

Q6: Can this fix itself?
Sometimes, it is caused by mild illness, but persistent cases need vet care.