Light-sensitive Eyes – Symptoms, Causes, and What You Can Do About It

What is Light Sensitivity?

Light sensitivity, also known as photophobia, is an increased sensitivity to light. Affected individuals react to sunlight, reflective surfaces, or artificial light sources and are easily dazzled. The cause of light sensitivity lies in each person's unique perception.

If eyes experience discomfort from daylight, bright artificial light, or screens, it indicates light sensitivity. Potential sources include sunlight, reflective surfaces (like roads or windows), snow, water, or sand reflections, and artificial lights such as neon tubes, LEDs, and lamps. Sensitivity can range from mild to severe, even causing significant eye pain.

People with lighter eye colours are more frequently affected due to lower melanin levels, allowing more sunlight into the eye and quicker glare.

How Does Light Affect the Eye?

How are the eyes and light sensitivity linked? Light entering the human eye is regulated by the pupil and iris. The pupil is the opening at the iris’s centre, and the iris, or "rainbow membrane," is the eye’s coloured part. Pupil size adjusts to control light reaching the retina, the eye’s innermost layer.

In bright light, the iris contracts, shrinking the pupil (miosis) to reduce light entry, preventing glare. In low light, the iris expands, enlarging the pupil (mydriasis), allowing more light in for better vision. This adjustment provides optimal light for clear vision.

What Causes Glare?

Glare occurs when excessive light hits the retina. Normally, pupil adjustments manage light entry, but disruptions to this process allow too much light, causing glare and making the eyes very sensitive to light.

Eyes Sensitive to Light and Vision Impairments

Increased light sensitivity can indicate a vision impairment, especially if the eyes are not corrected properly. For example, with an uncorrected binocular vision disorder, sensitivity to glare often rises, as the eyes adapt more slowly to brightness changes.

It may also signal degenerative myopia, a form of nearsightedness where visual acuity gradually declines, potentially leading to blindness. Additionally, uncorrected farsightedness (hyperopia) can result in symptoms such as light sensitivity, eye fatigue, double vision, and headaches.

What Are the Symptoms of Light-sensitive Eyes?

Primary symptoms of light sensitivity include an intense sensitivity to glare. Additional symptoms may include:

• Eye pain, especially under constant bright light

• Squinting or an urge to close the eyes

• Headaches

• Discomfort in bright light

• Red, blurry eyes

What Causes Light Sensitivity to Eyes?

Light sensitivity can be due to external factors or underlying conditions.

External Factors

Temporary light sensitivity can be caused by:

• Dry Eyes (Sicca Syndrome): Often from extended screen time or dry air.

• Allergies: Sensitivities to skincare products.

• Medication Side Effects: Some antibiotics and other drugs.

• Eye Surgery or Laser Treatment: Can cause temporary sensitivity.

Medical Conditions

Light sensitivity can also result from:

• Corneal damage

• External eye infections, such as conjunctivitis

• Internal eye infections, such as iris or choroid inflammation

• Cataracts

• Glaucoma

• Viral infections like herpes

• Retinal detachment

• Neurological conditions, such as migraines or cluster headaches

• Meningitis

• Rheumatic diseases, such as fibromyalgia or rheumatoid arthritis

• Chemotherapy, Chronic fatigue syndrome (CFS) and fatigue syndrome

• Traumatic brain injuries, brain injuries, brain haemorrhages, and brain tumours

What Can I Do About Light Sensitivity?

For temporary relief from light sensitivity, such as during a migraine attack or from corneal damage, wearing sunglasses can help. However, this should not become a permanent solution, as the eyes might adapt to reduced UV light, worsening sensitivity over time.

It’s important to medically determine the cause of increased light sensitivity to find an appropriate treatment.

When Should I See an Eye Doctor for Eyes Sensitive to Light?

Not every case of light sensitivity requires treatment. Sensitivity naturally increases with age and is more common in people with light-colored eyes (blue, green, grey) due to lower pigment levels.

If light sensitivity is sudden, intense, and doesn’t subside within a few hours, it’s advisable to see a doctor. Also, if accompanied by symptoms such as red eyes, tearing, or eye pain, medical consultation is recommended to determine the underlying cause.

How is the Diagnosis Made by the Doctor?

The diagnosis of light sensitivity should be made by a doctor. First, a medical history will be taken, and questions will be asked about the following topics:

• Family history

• Personal lifestyle

• Health conditions

• Vision

• Medication

• Symptoms

Afterward, a thorough examination will be conducted. This includes a procedure called ophthalmoscopy, an eye fundus examination. During this, the back of the eye—especially the retina—is carefully examined and assessed. This is done to detect eye diseases, but also other conditions such as high blood pressure, a brain tumor, or diabetes mellitus.

What Treatment Options Are There for Light Sensitivity?

There are several measures that can be taken to manage light sensitivity, such as wearing tinted lenses. An optician can advise you on this: There are options like lightly tinted lenses, photochromic lenses that adapt to different lighting conditions, or dark-tinted sunglasses. These reduce light exposure and can temporarily relieve the eyes. It’s important to emphasise that this is not a permanent solution, and the underlying cause of light sensitivity should be clarified so that appropriate treatment can be provided.

Treatment options vary depending on why the eyes are sensitive to light.

• Dry eyes can be effectively treated with eye drops or ointments from an eye doctor or pharmacy.

• For allergies, antihistamine eye drops from the pharmacy or a doctor can help.

• After eye surgery or laser treatment, you will receive medications in the form of eye drops, ointments, or gels to ensure optimal healing.

• For conditions where light sensitivity is a secondary symptom, such as neurological or rheumatic diseases, the primary condition will be treated first, followed by measures to address the light sensitivity.