Page contents
Photophobia is excessive sensitivity of the eyes to light: light that other people tolerate easily bothers you, makes you squint or causes you pain. It is not a disease but a symptom. The most common causes are dry eye and migraine. However, when it comes on suddenly in one eye, together with pain, redness or blurred vision, it points to inflammation of the cornea or of the inside of the eye and needs an examination the same day.
What Is Photophobia and Why Does Light Hurt?
The word literally means “fear of light”, but it has nothing to do with fear. It is genuine physical discomfort. Light is not detected only by the cells that form the image. The retina also has a separate group of cells that measures overall brightness, controls pupil size and our body clock, and is particularly sensitive to blue-green light. These cells connect, via the trigeminal nerve, with the same brain centres that process pain from the face and head. When the trigeminal nerve is already irritated, either by damage to the surface of the eye or by a migraine, light “turns up the volume” and becomes pain.
This explains three things: why conditions of the cornea, which has the densest nerve supply in the body, cause such intense photophobia; why migraine and photophobia go together; and why the cold, bluish light of screens and LED bulbs is more bothersome than the warm light of an incandescent bulb.
Photophobia or glare?
It is worth telling the two apart. In photophobia, light causes discomfort or pain. With glare, light does not hurt, but it scatters inside the eye and “washes out” the image, as when you drive towards the sun with a dirty windscreen. Glare is typical of cataract and of corneal haze. The two complaints can occur together, but they have different causes.
Eye Causes of Photophobia
Dry eye and blepharitis
The most common cause of chronic, mild photophobia in both eyes. When the tear film is unstable, the surface of the cornea becomes irregular, its nerves are exposed and light becomes bothersome, especially screen light, sun and wind. It comes with burning and a gritty feeling. See the pages on dry eye and blepharitis.
Abrasion, foreign body and keratitis
Any damage to the cornea causes intense photophobia, pain and watering, and the eye will not stay open. In contact lens wearers, a red eye that cannot tolerate light is keratitis until proven otherwise. The same applies to eye herpes and to ultraviolet burns after welding or exposure to snow.
Uveitis
Inflammation of the iris causes the most characteristic photophobia. Light forces the pupil to constrict, and when the iris is inflamed, every constriction hurts. The pain is deep, the redness is concentrated around the coloured part of the eye and vision becomes blurred. A useful sign is that the eye hurts even when light falls on the other, healthy eye, because both pupils react together. More on this under eye inflammation.
Conjunctivitis
Simple conjunctivitis causes only mild discomfort in light. Intense photophobia in “conjunctivitis” means the cornea is also involved, which often happens in the viral forms caused by adenovirus, one to two weeks after onset.
Dilated pupil
The wider the pupil, the more light gets in. This happens for 3 to 6 hours after the drops used for a dilated eye examination, after injury to the iris, and with certain medicines.
After eye surgery
In the first days or weeks after laser vision correction, especially with surface techniques, and after cataract surgery, sensitivity to light is expected and settles gradually. If instead of improving it gets stronger, together with pain or a drop in vision, get in touch immediately.
Congenital conditions and light-coloured eyes
People with a very light-coloured iris have less pigment to filter light and are bothered more easily, without this being a disease. Intense photophobia from childhood is a feature of albinism, absence of the iris (aniridia) and certain inherited retinal dystrophies.
Nervous System Causes
Migraine
This is the most common neurological cause. Eight out of ten people with migraine have photophobia during an attack, and many remain sensitive to light between attacks as well. Bright or flickering light can also trigger an attack. The eyes are normal on examination.
Meningitis and brain haemorrhage
Photophobia together with fever, a very severe headache, a stiff neck, vomiting or drowsiness is an emergency and needs immediate transfer to hospital. The same applies to a sudden, thunderclap headache, the worst of your life.
Concussion
After a blow to the head, sensitivity to light and screens can last for weeks or months.
Blepharospasm
In blepharospasm, the eyelids squeeze shut involuntarily and light is the main trigger for the spasms.
Other Causes
- Medicines: certain antibiotics, acne treatments, antihistamines, antidepressants, diuretics and others increase sensitivity to light or dilate the pupil
- Lack of sleep, fatigue, dehydration and alcohol
- Anxiety and panic attacks
- Long hours on screens in a dark room
- Constantly wearing dark glasses indoors, which makes the eyes even more sensitive
When Photophobia Is Urgent
Be examined the same day if your sensitivity to light:
- came on suddenly, especially in one eye
- comes with eye pain
- comes with a red eye or blurred vision
- affects someone who wears contact lenses
- followed an injury, a chemical splash or recent eye surgery
Go to hospital immediately if there is also fever, a very severe headache, a stiff neck, vomiting, confusion or a rash.
Photophobia in babies and children
A baby who avoids light, has constantly watering eyes and eyes that look large or cloudy must be examined urgently for congenital glaucoma. In older children, the most common causes are corneal abrasion, allergy, chronic blepharitis and migraine. See the page on paediatric ophthalmology.
How Photophobia Is Diagnosed
Your history gives half the answer: one eye or both, sudden or long-standing, with or without pain, with or without headache, and which medicines you take. During the examination we measure your vision, check your pupils and use the slit lamp to examine the eyelids, the tears and the cornea with a dye, as well as the inside of the eye for inflammatory cells. Then the eye pressure is measured and the back of the eye examined. If the eyes are normal and the photophobia persists, the investigation continues with a neurologist.
Treatment
Treatment means treating the cause. Dry eye is treated with artificial tears and eyelid care, keratitis with the appropriate antimicrobials, uveitis with anti-inflammatory drops and drops that rest the iris, and migraine with its own medication. Once the cause is under control, the photophobia settles. In the meantime, and for people with chronic sensitivity, the following help.
The right glasses
- Outdoors: sunglasses with UV400 protection, preferably polarised to cut reflections from the road, the sea and snow, with wraparound frames, and a hat with a brim
- Indoors: no dark glasses. The eyes adapt to the dark and become more and more sensitive, creating a vicious circle. If you need something, lenses with a light rose tint that filters blue-green light, and an anti-reflective coating, are preferred
- Photochromic lenses for people who go in and out often
Lighting and screens
- choose warm, indirect light instead of cold overhead bulbs
- avoid flickering bulbs and replace old ones
- place your screen at right angles to the window, not facing it or with the window behind it
- adjust screen brightness to match the room and turn on night mode in the evening
- do not look at your phone in a completely dark room
- take frequent breaks and use artificial tears. See the tips on dry eyes at the office
General measures
Enough sleep, good hydration, limiting alcohol and, for people with migraines, recognising and avoiding their triggers. Gradual, controlled exposure to natural light helps the eyes regain their tolerance, whereas avoiding light completely reduces it.
Book an Appointment
If light bothers you more than it used to, a slit lamp examination shows whether the surface of the eye is to blame, which is the most common and most easily treatable cause. For sudden photophobia with pain or a red eye, call so that we can see you the same day. The clinic is in Neo Psychiko, Athens: call 210 677 0007.
Frequently Asked Questions about Photophobia
Why does light suddenly bother me?
Sudden sensitivity to light is usually caused by a corneal abrasion or inflammation, uveitis or migraine. If it affects one eye and comes with pain, redness or blurred vision, it needs an examination the same day.
Is photophobia a sign of a serious condition?
Most of the time, no. It is caused by dry eye or migraine. It becomes serious when it is combined with pain and a red eye, or with fever, a severe headache and a stiff neck, which need urgent medical assessment.
Should I wear sunglasses indoors?
Not routinely. Dark glasses indoors make the eyes adapt to the dark and increase sensitivity. Choose softer lighting instead and, if needed, lenses with a light tint and an anti-reflective coating.
Do screens cause photophobia?
They do not damage the eyes, but they reduce blinking and dry out the eye surface, which increases sensitivity to light. Breaks, artificial tears, the right brightness and night mode all help.
What is the link between photophobia and migraine?
A close one. Most people with migraine have photophobia during attacks, and bright light can trigger an attack. This is because the pathways for light and pain meet in the same brain centres.
Are light-coloured eyes more sensitive to light?
Yes, to some extent. A light-coloured iris has less pigment and lets more light through. It is not a disease, but it makes wearing good sunglasses more important.
Questions about your case?
Dr. Skouteris will examine you at his practice in Neo Psychiko and explain your options.
Ophthalmic surgeon trained at the John Radcliffe University Hospital in Oxford and Fellow of the European Board of Ophthalmology (FEBO).
Full profile