Conjunctiva

The conjunctiva is a thin, clear membrane on the front of the eye and inside the eyelids. It is an anatomical structure, not a disease or diagnosis.

The conjunctiva covering the white part of the eye is called the bulbar conjunctiva. The white tissue underneath is the sclera, the strong outer wall of the eyeball.

The part lining the inside of the eyelids is called the palpebral conjunctiva. Between these two areas, the membrane folds back on itself. This flexible fold allows your eyelids and eyes to move without pulling tightly on the tissue.

The conjunctiva does not cover the cornea. The cornea is the clear, curved window over the coloured iris and pupil. The border where the cornea, sclera, and conjunctiva meet is called the limbus.

Because the conjunctiva is almost transparent, you usually see the white sclera and small blood vessels beneath it. When these vessels widen, the eye can look pink or red.

The conjunctiva helps maintain a smooth, moist surface over the eye. It works with your eyelids, tear glands, and cornea each time you blink.

Some conjunctival cells make mucus. This mucus forms part of the tear film—the thin layer of fluid spread across the eye. It helps tears coat the surface evenly rather than collecting in separate drops.

Other parts of the tear film provide water and oils. Together, these components reduce friction, wash away small particles, and support a clear optical surface. A stable tear film matters for comfortable blinking and sharp vision.

The conjunctiva also forms a physical barrier between the eye and the outside environment. Immune cells within the tissue can respond to germs, allergens, and irritants. This protective response can cause redness, swelling, discharge, or itching when the conjunctiva is affected by another condition.

Its network of small blood vessels supplies oxygen and nutrients to the tissue. These vessels may become easy to see during inflammation. Occasionally, one breaks and releases blood beneath the clear membrane, creating a sharply defined red patch.

The conjunctiva is sensitive, but it is not responsible for vision itself. Light passes through the cornea and lens to reach the retina at the back of the eye. Problems limited to the conjunctiva often do not reduce vision, although discharge or an uneven tear film may briefly make sight seem blurry.

Clinicians examine the conjunctiva because its appearance can provide useful information about the eye’s surface.

Redness may come from widened conjunctival blood vessels. The pattern of redness, together with pain, discharge, itching, vision changes, and light sensitivity, helps a clinician consider possible causes. Redness alone does not identify a specific condition.

The inner eyelid may be examined for swelling, irritation, trapped material, or changes linked to allergy. A clinician may gently turn the upper eyelid outward if a foreign object could be hidden underneath it.

The conjunctiva also matters during contact lens use. A red or uncomfortable eye in someone wearing contact lenses needs particular attention because conditions affecting the cornea can initially resemble simple conjunctival irritation.

During some eye operations, the conjunctiva may be moved, opened, or used to cover another area. It usually heals readily, but follow-up instructions depend on the procedure performed.

Changes in conjunctival colour can occasionally support a wider medical assessment. For example, marked paleness may be considered alongside blood tests for anaemia. Yellow colouring may be assessed with other signs of jaundice. The appearance of the conjunctiva cannot confirm either condition by itself.

Several conditions and situations can involve the conjunctiva:

• Conjunctivitis means inflammation of the conjunctiva. Causes include viruses, bacteria, allergies, chemicals, and other irritants. “Pink eye” is a common name for conjunctivitis, but not every red eye is conjunctivitis.
• Subconjunctival haemorrhage is bleeding beneath the conjunctiva. It usually appears as a bright red patch over the white of the eye. It can follow coughing, straining, rubbing, or minor injury, although no clear cause is always found.
• Chemosis means swelling of the conjunctiva. The tissue may look raised, loose, or blister-like. It can occur with allergy, infection, injury, or other inflammation.
• Pinguecula is a small, raised area on the conjunctiva near the cornea. A pterygium is a wedge-shaped growth that extends from the conjunctiva onto the cornea.
• Foreign bodies and scratches can affect the conjunctiva, especially beneath an eyelid. Dust, plant material, metal fragments, and other particles may also injure the cornea.
• Conjunctival cysts, growths, and tumours can occur. Many growths are not cancer, but a new, changing, raised, or unusually coloured area should be examined.

Some serious eye conditions can look like conjunctivitis at first. These include corneal infection or inflammation, inflammation inside the eye called uveitis, and sudden pressure rises from acute angle-closure glaucoma.

Seek urgent eye care for redness accompanied by significant pain, sensitivity to light, reduced or distorted vision, a recent eye injury, or a feeling that something remains embedded in the eye. Contact lens wearers should seek prompt assessment for a red, painful, light-sensitive, or unusually watery eye.

A chemical splash is an emergency. Begin rinsing the eye immediately with plenty of clean, lukewarm water and continue while arranging emergency help. Do not delay rinsing to search for a particular solution.

A healthy conjunctiva does not need routine testing on its own. It is usually checked as part of a standard eye examination.

If you develop an eye-surface problem, useful details to record include:

• When the change began and whether one or both eyes are involved
• Whether there is itching, pain, discharge, light sensitivity, or altered vision
• Recent contact lens use, illness, injury, chemical exposure, or new eye products
• A clear photograph if the appearance changes before your appointment

Ask what part of the eye is affected rather than assuming that all redness comes from the conjunctiva. You can also ask whether the cornea has been examined and whether contact lenses should remain out while the eye is being assessed.

An optometrist or ophthalmologist can inspect the conjunctiva with magnification and a bright light. A slit lamp provides a detailed view of the eye’s front structures. Fluorescein, a temporary orange dye, may be used to reveal damage to the eye’s surface. Swabs or other tests are used only in selected situations.

For mild redness or irritation without pain, vision change, injury, or contact lens concerns, routine advice from a pharmacist, primary care clinician, or eye-care professional may be appropriate. Persistent, recurrent, or unexplained changes should be assessed rather than repeatedly self-treated.

Is the conjunctiva the white of the eye?

No. The white part is mainly the sclera. The conjunctiva is the clear membrane lying over it.

Is the conjunctiva the same as the cornea?

No. The conjunctiva covers the sclera and lines the eyelids. The cornea is the clear window in front of the iris and pupil.

Why does the conjunctiva look red?

Its small blood vessels become more visible when they widen. This can happen with dryness, irritation, allergy, infection, injury, or inflammation. The appearance alone does not show the cause.

Can conjunctival problems affect vision?

Discharge or an unstable tear film may cause temporary blur. Persistent vision loss or marked visual change suggests that more than the conjunctiva may be involved and needs prompt assessment.

Can the conjunctiva heal?

Minor surface irritation often settles as the tissue renews itself. Healing after an injury or procedure depends on what happened and whether deeper eye structures were affected.

Can you see your own conjunctiva?

Yes. The bulbar conjunctiva lies over the visible white of the eye. You can also see part of the palpebral conjunctiva by gently pulling down the lower eyelid. Do not attempt to remove embedded material or manipulate an injured eye.