Eye Redness

Many people notice red or bloodshot eyes at some point, which can look alarming and feel uncomfortable. Eye redness usually happens when small blood vessels on the surface of the eye become swollen or irritated. Allergies, infections like conjunctivitis, dry eyes, or mild injuries often cause this reaction.

The most common reasons for red eyes are inflammation, allergies, and infections. Some causes may be minor and clear up quickly, while others might need a doctor’s care. Knowing why your eyes turn red can help you figure out what to do next.

Definition of Symptom

Eye redness means the white part of the eye, called the sclera, looks red or pink instead of white because tiny blood vessels on the eye’s surface swell or widen. People may notice the whole eye looks red, or only certain spots are affected. Both eyes or just one eye can show redness. Some common signs that go with eye redness are:

• Mild irritation or itching
• Watery or sticky discharge
• A feeling that something is in the eye

Some people do not feel any discomfort beyond the redness. Others may notice pain or blurred vision, but these can signal a more serious problem. Eye redness is a symptom, not a disease itself. It often points to an underlying cause like irritation, infection, or injury.

Appearance	Possible Feeling
Light pink color	Mild itching or dryness
Deep red patches	Stinging or burning
Bright red streaks	Gritty feeling

Possible Causes/Diseases Condition

Allergies, dry eyes, infections, injuries, eyelid inflammation, and increased eye pressure often make blood vessels on the surface of the eye swell or become irritated. Common causes include:

• Allergies: Pollen, dust, or pet dander can make eyes red and itchy.
• Dry Eyes: Not enough tears or poor tear quality can lead to redness.
• Infections: Pink eye (conjunctivitis) and other infections often cause redness and discharge.
• Injury: Scratches or small foreign objects can irritate the eye, leading to redness.
• Blepharitis: Swelling of the eyelid edges can make the eye look red.
• Glaucoma: Increased pressure inside the eye can sometimes cause redness.

Other triggers include sun exposure, contact lens use, and exposure to smoke or chemicals. Rubbing the eyes too much can also make the redness worse.

Cause	Typical Symptoms
Allergies	Itching, watering, redness
Pink Eye	Redness, discharge
Dry Eyes	Burning, gritty feeling
Injury/Foreign Body	Pain, redness, tearing
Blepharitis	Sore eyelids, crusting

Other Non-Disease Causes

Not all cases of eye redness come from disease or infection. Everyday factors often make eyes look red.

• Irritants: Smoke, dust, and strong odors can lead to redness. Chlorine from swimming pools or pollution can also irritate the eyes.
• Allergies: Seasonal allergies or pet dander often cause eye redness. The eyes react to allergens by becoming red, itchy, and watery.
• Contact Lenses: Wearing contact lenses too long or not cleaning them well may irritate the eyes. Old or damaged lenses can also increase the risk of redness.
• Fatigue: Lack of sleep or eye strain from screens can make blood vessels on the eye’s surface more visible.

Here is a quick list of non-disease causes:

• Irritants (smoke, dust, chemical fumes)
• Allergies (pollen, pet dander)
• Contact lens use
• Fatigue or lack of sleep
• Dry air or wind
• Rubbing the eyes

Cause	Example	Effect on Eyes
Irritants	Smoke, chlorine, pollution	Redness, irritation
Allergies	Pollen, animals	Itchy, red
Contact lenses	Overuse, poor cleaning	Red, dry
Fatigue/Screen Time	Long hours on computer or phone	Red, tired-looking

Irritants and strain from daily life are among the most frequent reasons for red eyes not linked to disease.

How It Causes the Symptom

When irritation or inflammation affects the eye, small blood vessels on the surface expand and become more visible, making the eye look red. Allergies, infections, dry eyes, or injury often trigger this response. As the vessels expand, more blood flows to the area, giving the eye a red or bloodshot look. Other symptoms can show up with redness:

• Itching or burning
• Watery eyes
• Swelling
• Sensitivity to light

For example, allergens or dust can make the eyes water and itch. Infections like pink eye can cause both redness and discharge. Dry air or staring at screens for too long can dry out the surface, leading to irritation.

Possible Complications

If eye redness does not go away, or if it comes with other symptoms, complications may develop. Pain, changes in vision, or discharge can signal a more serious problem. Some complications linked to eye redness include:

• Eye infections such as conjunctivitis
• Corneal ulcers (open sores on the eye’s surface)
• Vision loss or blurry vision
• Glaucoma (high pressure in the eye)
• Uveitis (inflammation inside the eye)

Without proper care, these problems might get worse and even lead to permanent damage. Warning signs that need quick medical attention include:

Symptom	Possible Concern
Eye pain	Infection, Glaucoma
Sudden vision changes	Retinal problem
Light sensitivity	Uveitis, Infection
Pus or thick discharge	Serious infection

Long-term or repeated redness may also lead to chronic irritation, scarring, or discomfort.

When to Seek Medical Attention

Not all cases of red eyes are emergencies, but some signs show that professional care is important. People should seek medical help if they notice:

• Sudden vision changes or blurred vision
• Severe pain or discomfort in the eye
• Sensitivity to light
• Nausea or vomiting along with eye symptoms
• Eye redness after a chemical splash or injury

If red eyes come with headache, fever, or you see halos around lights, contact a doctor right away. If children have red eyes with pain, discharge, or vision changes, take them to a healthcare provider promptly. If redness does not go away after a few days, or if it keeps getting worse, get checked.

Possible Serious Causes

Symptom	Possible Condition
Severe pain	Corneal ulcer, glaucoma
Sudden vision loss	Retinal problem
Pus or thick discharge	Eye infection
Trauma	Injury or foreign object