SymptomEyes & vision
Night Vision Problems: Causes and Treatment
Night vision problems mean you see much worse than others in dim light or darkness, or take a long time to adjust when the lights go down. Doctors call severe night blindness nyctalopia. Common causes are uncorrected nearsightedness, cataracts, glare from dry eyes and normal aging. Less often, it signals vitamin A deficiency, glaucoma, diabetic eye disease or an inherited retinal disease such as retinitis pigmentosa. Most causes are treatable.
Also called: Night blindness, nyctalopia, poor night vision, trouble seeing in the dark, difficulty driving at night
At a glance
- What it is
- Reduced vision in low light, slow adaptation to darkness, or troublesome glare and halos at night.
- Common causes
- Nearsightedness, cataracts, dry eyes, aging, previous laser eye surgery.
- Less common causes
- Vitamin A deficiency, retinitis pigmentosa, glaucoma, diabetic retinopathy, keratoconus.
- Key test
- A full eye exam with dilated retina check. Specialist tests for inherited conditions.
- Treatment
- New glasses, cataract surgery, dry eye treatment, vitamin A, or management of retinal disease.
When to get help
Call 911 or go to the ER
- Sudden loss of vision, a curtain over part of your vision, or a shower of new floaters and flashes
- Painful red eye with blurred vision, halos around lights, headache and nausea, which can be acute glaucoma
See a doctor within a day or two
- Night vision getting worse quickly over weeks
- Night blindness with dry, rough eyes, white foamy spots on the white of the eye, or poor diet or gut problems (possible vitamin A deficiency)
- Loss of side vision, bumping into things or tripping in dim light
Book a routine appointment
- Difficulty driving at night, glare from headlights or halos around lights
- Taking longer than before to adjust when moving from light to dark
- A family history of retinitis pigmentosa or other retinal disease
Usually safe to manage at home
- Slightly slower dark adaptation with age, when a recent eye exam was normal
How night vision works
The retina has two types of light-sensing cells. Cones work in bright light and see color and detail. Rods, mostly in the outer retina, work in dim light and give side vision. Rods use a pigment called rhodopsin, which needs vitamin A. Full dark adaptation takes about 20 to 30 minutes. Night vision problems happen when rods are damaged, light is scattered before it reaches the retina, or the eye focuses poorly when the pupil widens in the dark.
Common causes
Uncorrected nearsightedness
Myopia often worsens slightly in the dark ("night myopia") because the pupil widens. Distant signs and road markings blur. An updated glasses prescription often fixes it.
Cataracts
A cataract clouds the lens. It scatters light, causing glare, halos and starbursts around headlights and streetlights, and dims vision overall. It is the most common cause of worsening night vision in people over 60.
Dry eye and glare
An uneven tear film scatters light. Dry eye causes blurred, fluctuating vision and glare that improves with blinking.
Aging
From middle age, pupils get smaller, the lens yellows and rods become fewer, so older people need more light to see and recover from glare more slowly. This is gradual and mild.
After laser eye surgery or with certain lenses
LASIK and other refractive surgeries can cause halos and glare at night, especially early on or with large pupils. Some multifocal contact lenses and implants do the same.
Astigmatism and keratoconus
Uneven corneal shape causes streaky, smeared lights. Keratoconus is a progressive thinning and bulging of the cornea, usually starting in the teens or twenties.
Less common but important causes
| Cause | Clues |
|---|---|
| Vitamin A deficiency | Night blindness is the earliest sign, with dry eyes and foamy spots on the white of the eye. Seen with malnutrition, weight-loss surgery, pancreatic disease, celiac disease, Crohn's, liver disease |
| Retinitis pigmentosa | Inherited. Night blindness from childhood or adolescence, followed by gradual loss of side (tunnel) vision |
| Glaucoma | Gradual loss of side vision, often unnoticed until advanced. Some glaucoma drops narrow the pupil and dim night vision |
| Diabetic retinopathy | Diabetes, blurred or patchy vision, and laser treatment can reduce night vision |
| Congenital stationary night blindness | Inherited, present from birth, does not worsen |
| Medicines | Pilocarpine drops, some antimalarials (hydroxychloroquine retinopathy), and others |
How doctors find the cause
An optometrist or ophthalmologist will:
- Ask when it started, whether it is getting worse, and about family history, diet, gut problems, surgery and medicines.
- Test sharpness of vision and check your glasses prescription.
- Examine the cornea, tear film and lens with a slit lamp.
- Dilate the pupils to examine the retina and optic nerve.
- Test side vision (visual fields) and eye pressure.
If inherited retinal disease is suspected, an electroretinogram (ERG) measures how rods and cones respond to light, and genetic testing can identify the gene. Blood tests check vitamin A levels when deficiency is possible.
Treatment
- Glasses or contact lenses for myopia or astigmatism, sometimes a dedicated pair for night driving with anti-reflective coating.
- Cataract surgery replaces the cloudy lens and usually transforms night vision.
- Dry eye treatment: lubricating drops, warm compresses and treating eyelid inflammation.
- Vitamin A supplementation for confirmed deficiency, under medical supervision because too much is toxic, and avoided in high doses during pregnancy. Night vision often improves within days to weeks.
- Retinitis pigmentosa: there is no cure for most types, but low-vision aids, mobility training and, for one gene form (RPE65), gene therapy are available. Research trials are ongoing.
- Glaucoma and diabetic eye disease: controlled with drops, laser and other treatments to protect remaining vision.
Night driving safety
- Keep windshields, headlights and glasses clean.
- Dim the dashboard lights and use the night mirror setting.
- Look toward the right edge of the lane, not into oncoming headlights.
- Avoid tinted "night driving" glasses, which reduce the light reaching your eyes.
- Stop driving at night if you cannot see road signs or pedestrians clearly, and get your eyes checked.
Frequently asked questions
What causes poor night vision?
Common causes are nearsightedness, cataracts, dry eye, astigmatism and the normal changes of aging. Less common causes include vitamin A deficiency, glaucoma, diabetic retinopathy and inherited retinal diseases such as retinitis pigmentosa. An eye exam can find the cause.
Can night blindness be cured?
It depends on the cause. Night blindness from cataracts, an outdated prescription, dry eye or vitamin A deficiency usually improves with treatment. Night blindness from retinitis pigmentosa and other inherited retinal conditions cannot usually be reversed, though gene therapy helps one rare type.
Does vitamin A improve night vision?
Only if you are deficient. In vitamin A deficiency, supplements restore night vision. If your vitamin A level is normal, extra vitamin A or carrots will not improve night vision, and high-dose supplements can cause liver damage and birth defects.
Why do I see halos around lights at night?
Halos are usually caused by cataracts, dry eye, uncorrected astigmatism or previous laser eye surgery. Halos with a painful red eye, headache and nausea can mean acute angle-closure glaucoma, which is an emergency.
Is it normal for night vision to get worse with age?
Some decline is normal: older eyes have smaller pupils, a yellower lens and fewer rods, so they need more light and recover from glare more slowly. A noticeable or rapid worsening should be checked, because cataracts and other treatable conditions are common.
Sources
This guide was written from current patient and clinical guidance, including:
- American Academy of Ophthalmology: What Is Night Blindness?
- National Eye Institute: Retinitis Pigmentosa
- MedlinePlus: Night blindness
- World Health Organization: Vitamin A deficiency
- American Optometric Association: Night vision and driving