Eye redness is a condition in which the fine blood vessels located in the white part of the eye become enlarged, irritated, or inflamed, causing the eye to appear noticeably red. Medically known as “conjunctival hyperemia,” this condition may result from a wide range of causes, from simple environmental irritation to serious eye diseases.

The eye is one of the most delicate organs in the human body, and even minor discomforts may cause the blood vessels to become more visible. Sometimes eye redness resolves on its own within a short time, while in other cases it may persist and affect daily life and visual comfort. Therefore, understanding the underlying causes and consulting a specialist when necessary is extremely important.

Experienced eye specialist Op. Dr. Diclehan emphasizes that eye redness is not always an innocent symptom and should be carefully evaluated.

Do Allergic Reactions Cause Eye Redness?

Yes. One of the most common causes of eye redness is allergic reactions. Known as allergic conjunctivitis, this condition occurs when allergens such as pollen, dust, house mites, pet hair, perfumes, makeup products, or lens solutions irritate the eye surface. Typical symptoms include:

• Severe itching
• Watery eyes
• Burning sensation
• Redness in both eyes
• Runny nose or sneezing

Allergic eye redness is often seasonal and increases particularly during spring. It may become more pronounced in people who spend long periods outdoors. Op. Dr. Diclehan states that proper eye hygiene and protection from allergens are very important in people with allergic eye structure.

Can Infections Cause Eye Redness?

Yes. Bacterial, viral or rarely fungal infections may lead to inflammation and become one of the major causes of eye redness. The most common infectious eye condition is conjunctivitis. Symptoms may include:

• Yellow, white or green discharge
• Eyelids sticking together in the morning
• Burning and stinging
• Light sensitivity
• Marked redness

Viral conjunctivitis is contagious and spreads easily through shared personal items. Op. Dr. Diclehan warns that using eye drops without medical advice may worsen the condition and stresses the importance of medical examination.

Can Dry Eye Cause Eye Redness?

Yes. Dry eye is one of the most frequent causes. When the eye surface is not adequately lubricated, the protective tear film becomes unstable and irritation develops, leading to redness. Dry eye is more common in:

• People who spend long hours at screens
• Contact lens users
• Those experiencing hormonal changes
• People exposed to air-conditioning
• Smokers

Symptoms may include burning, stinging, dryness and blurred vision. Op. Dr. Diclehan notes that proper use of artificial tears may help relieve redness caused by dryness.

Can Eye Strain Cause Eye Redness?

Overuse of the eyes may also trigger redness. Situations such as

• Prolonged screen exposure
• Reading in poor lighting
• Sleep deprivation
• High stress

may cause strain and irritation of the eye surface, making blood vessels more visible. Taking regular breaks and maintaining good sleep hygiene are important preventive measures.

Can Contact Lens Use Cause Eye Redness?

Yes. Contact lenses may cause serious irritation or infection if not used hygienically. Risky situations include

• Sleeping with lenses
• Poor hygiene
• Incorrect lens solutions
• Using expired lenses

Even small mistakes may cause significant problems. Op. Dr. Diclehan recommends regular eye examinations and strict hygiene for lens users.

Do Trauma and Eye Injuries Cause Redness?

Blows to the eye, scratches, foreign bodies or chemical exposure may cause eye redness. Sometimes a bright red patch appears on the white of the eye — called subconjunctival hemorrhage  which is usually harmless. However, urgent care is needed if there is:

• Severe pain
• Vision loss
• Blurred vision
• Restricted eye movement
• Dizziness or nausea

Op. Dr. Diclehan emphasizes that eye injuries should never be ignored.

Can Glaucoma Cause Eye Redness?

Glaucoma (eye pressure disease) is a serious condition involving damage to the optic nerve. In acute glaucoma attacks, symptoms may include:

• Severe eye pain
• Marked redness
• Blurred vision
• Headache
• Nausea

This is a medical emergency and may cause permanent vision loss if not treated immediately.

Can Systemic Diseases Cause Eye Redness?

Yes. Conditions such as

• Thyroid disorders
• Rheumatologic diseases
• Diabetes
• Hypertension
• Kidney diseases

may affect the eye vessels and cause redness. Infections and immune disorders may also trigger symptoms.

Environmental and Lifestyle Factors

Important triggers include

• Cigarette smoke
• Air pollution
• Wind
• Sunlight
• Chlorinated pool water
• Alcohol use
• Inadequate hydration

These may irritate the eye surface and cause redness.

When Is Eye Redness Dangerous?

Seek urgent medical help if you experience

• Sudden and severe pain
• Vision loss
• Change in pupil size
• Redness after trauma
• Chemical exposure
• Fever with redness
• Rapidly worsening redness in children

Early diagnosis plays a key role in preventing permanent damage.

How Can Eye Redness Be Prevented?

Helpful habits include:

• Regular eye examinations
• Strict hygiene with lenses and cosmetics
• Limiting screen time
• Avoiding smoking and alcohol
• Washing hands frequently
• Avoiding allergens
• Using artificial tears when needed
• Wearing sunglasses outdoors

Eye redness is often caused by simple, treatable conditions  but in some cases, it may signal a serious eye disease. Persistent redness, pain, discharge, light sensitivity or vision loss should never be ignored.

Experienced eye specialist Op. Dr. Diclehan stresses that proper evaluation of eye redness is essential to reduce the risk of vision loss and protect long-term eye health.