At a glance
- Night vision problems (nyctalopia) mean difficulty seeing in low light or while driving at night.
- Common causes include cataract, uncorrected short-sightedness and dry eye.
- Less commonly it signals a retinal condition, so persistent problems deserve an eye check.
- Often it is correctable with glasses or cataract treatment.
What night vision problems are
Night vision problems describe difficulty seeing in dim light or after dark, or trouble adjusting when you move from a bright place into a darker one. You might find that a poorly lit room, a shaded car park or an evening walk feels far more difficult than the same setting in daylight. It is important to remember that poor night vision is a symptom rather than a disease in its own right. It points to an underlying cause that is worth identifying, because that cause guides what can be done to help. Many causes are common and correctable, while a smaller number reflect a condition of the retina or optic nerve that benefits from early attention. Because the eye relies on light-sensitive cells in the retina to work in dim conditions, anything that reduces the light reaching them, or affects how they respond, can make low-light vision harder.
Symptoms and situations
Night-vision difficulty shows itself in familiar everyday situations, and recognising the pattern often points towards the cause. Common experiences include:
- Trouble driving at night, when road signs, lane markings and pedestrians become harder to pick out.
- Glare and haloes around oncoming headlights or bright street lamps, which can be dazzling and slow to fade.
- Slow adjustment when entering a dark room from a bright one, so that you feel briefly “blind” before your eyes settle.
- Stumbling, hesitating or feeling unsteady in low light, such as on stairs or an unlit path.
Some people notice the problem mainly as tiredness or eye strain after driving in the dark, while others describe a general sense that dim environments have become more demanding than they used to be. It also helps to notice whether both eyes are affected equally, whether the trouble is worse in rain or with wet roads scattering light, and whether it eases when you rest or when lighting improves. Noticing which situations trouble you, and whether the difficulty is stable or slowly worsening, is useful information to share at an eye check.
Common causes
Most night-vision difficulty comes from ordinary, treatable causes affecting the front of the eye or the glasses prescription:
- Uncorrected short-sightedness or an out-of-date prescription. Myopia and astigmatism blur distance vision, and this is often more noticeable in the dark when the pupil is wider. Glasses that no longer match your eyes have the same effect.
- Cataract. A clouding of the eye’s natural lens scatters incoming light, which commonly causes glare, haloes and hazy night vision. This is a very relevant cause in older adults, in whom cataract becomes increasingly common, and it is a frequent reason for finding night driving harder with age.
- Dry eye. An unstable tear film blurs vision intermittently and worsens night-time glare, particularly in air-conditioned environments and after long screen use.
- Side effects of some eye conditions or treatments. Certain conditions of the eye, and some people after refractive surgery, notice glare and haloes in low light, which often settle with time or with management of the underlying issue.
Important medical causes
Less often, poor night vision reflects a condition of the retina or optic nerve that is worth detecting early. Glaucoma can gradually reduce peripheral and low-light vision. Retinal conditions such as retinitis pigmentosa, which is inherited, characteristically affect side vision and night vision, often before central daytime vision is disturbed. Diabetic eye disease can damage the retina and its blood vessels and may affect vision including in dim conditions, which is one reason regular screening matters for anyone with diabetes. Rarely, severe vitamin A deficiency impairs the retina’s ability to work in low light. These causes are far less common than cataract or refractive error, but because early treatment protects sight, persistent or progressive night-vision loss deserves a proper look.
How it is assessed
Assessment starts with a straightforward eye test to check your prescription and overall eye health. An eye specialist or optometrist measures your vision, examines the lens for cataract and looks at the retina and optic nerve. If a refractive cause is found, updating the glasses may be all that is needed. If the examination raises the possibility of a retinal or nerve cause, further tests can be arranged, such as a visual field check to map side vision or imaging of the retina. Sharing when the problem began, which situations are affected, and whether it is steady or worsening helps direct the assessment.
Treatment
Treatment depends entirely on the cause, which is why identifying it matters. Options include:
- Updating glasses. Correcting short-sightedness or astigmatism, or renewing an out-of-date prescription, often restores clearer night vision, and anti-reflective lens coatings can reduce glare.
- Cataract surgery when a cataract is the cause and it is interfering with daily life, such as night driving.
- Treating dry eye to stabilise the tear film and reduce night-time glare.
- Managing any underlying eye disease such as glaucoma, diabetic eye disease or a retinal condition, guided by an eye specialist.
Alongside treatment, some practical steps make night driving safer. Keep your glasses and windscreen clean so that light is not scattered further, keep your prescription current, allow your eyes time to adjust before setting off, and arrange an eye check if night driving has become difficult. These measures do not replace treating the cause, but they help in the meantime.
When it is more urgent
Most night-vision difficulty develops slowly and is not an emergency, but some patterns need prompt specialist attention. See an eye specialist promptly if you notice a fairly sudden decline in night or side vision, new flashes and floaters, or a shadow or “curtain” spreading across your vision, as these can signal a retinal problem. Eye pain with haloes, or vision that is progressively narrowing into tunnel vision, also warrants urgent review. Any sudden loss of vision needs emergency eye care without delay.
When to see a doctor or eye specialist
An optometrist can update your glasses and detect many causes, and is a reasonable first stop for gradual night-vision difficulty. See an eye specialist (ophthalmologist) if night vision is steadily worsening, if glare and haloes are troublesome, or if you notice any loss of side vision, since these may point to cataract needing treatment or to a retinal or glaucoma cause. In Singapore you can arrange an eye check through an optometrist or a private eye clinic, and complex or progressive problems may be referred to a centre such as the Singapore National Eye Centre. HealthHub offers general eye-health information. Many causes are treatable, and retinal conditions in particular benefit from early detection, so persistent difficulty is always worth having assessed.
Common questions
Why is night driving harder as I get older?
Age-related changes such as early cataract and a smaller pupil reduce the light reaching the retina and increase glare, making night driving harder; an eye check can help.
Can glasses improve night vision?
Yes, if uncorrected short-sightedness or astigmatism is the cause; anti-reflective lenses also reduce glare.
Is poor night vision a sign of a serious problem?
Usually it reflects cataract or refractive error, but progressive loss or loss of side vision should be checked for retinal or glaucoma causes.
Related guides
Sources
- Singapore National Eye Centre — cataract and night vision.
- American Academy of Ophthalmology — night vision.
- HealthHub Singapore — eye health.
This article is for general information only and does not replace a consultation with a qualified eye-care professional. If you have sudden vision loss, severe eye pain or an eye injury, seek urgent care.