Vision Problems: What Your Symptoms Mean

What different vision symptoms suggest

Gradual vision problems

Refractive errors

Nearsightedness (myopia), farsightedness (hyperopia) and astigmatism are the most common causes of blurred vision at any age. An eye test and glasses or contact lenses fix them.

Presbyopia

From the early to mid 40s, the lens stiffens and close focusing becomes harder. People hold books farther away. Reading glasses or multifocals help.

Dry eye and eye strain

Fluctuating blur that clears with blinking, gritty or burning eyes, and tiredness after screens. Breaks, blinking and lubricating drops help.

Cataract

Clouding of the lens causes blur, glare, halos around lights, faded colors and poor night vision, usually after 60. See cataract.

Glaucoma

The common open-angle form damages the optic nerve silently, gradually narrowing side vision, often without symptoms until late. Regular eye exams catch it. See glaucoma.

Macular degeneration and diabetic eye disease

Macular degeneration blurs and distorts central vision. Diabetic retinopathy may be silent until advanced, which is why yearly eye exams are advised for people with diabetes.

Sudden vision problems

Stroke and TIA

A stroke can cause sudden loss of vision in one eye or the same half of vision in both eyes, or double vision. A transient ischemic attack (TIA) can cause vision loss in one eye that lasts minutes, like a curtain coming down, then recovers. This is a warning sign of stroke. See stroke.

Retinal detachment

New floaters, flashes of light and a shadow spreading from the edge of vision. Needs surgery within hours to days. See retinal detachment.

Acute angle-closure glaucoma

A sudden rise in eye pressure causing a painful red eye, blurred vision, halos, headache, nausea and vomiting. It can cause permanent loss within hours. See acute glaucoma.

Giant cell arteritis

Inflammation of arteries in people over 50 causing headache, scalp tenderness, jaw pain on chewing and sudden vision loss. Urgent steroids prevent blindness. See giant cell arteritis.

Optic neuritis

Inflammation of the optic nerve, often in young adults and linked with multiple sclerosis, causing blurred or dim vision in one eye over days, with pain on eye movement and washed-out colors.

Migraine aura

Shimmering zigzag lines or blind spots spreading over 5 to 60 minutes, followed by headache. A first-ever aura, or one lasting longer than an hour, should be assessed.

How vision problems are assessed

An eye professional will check visual acuity in each eye, test your glasses prescription, examine the front of the eye with a slit lamp, measure eye pressure, check pupils and eye movements, and examine the retina after dilating drops. Additional tests include visual fields, OCT scans of the retina and optic nerve, and photographs. Sudden symptoms may need blood tests, brain imaging or a stroke assessment.

To learn more about the eye conditions behind these symptoms and how each is treated, see common vision problems and eye conditions.

Protecting your vision

• Have a comprehensive eye exam regularly: adults with no symptoms should have a baseline exam by 40, and every 1 to 2 years from 65.
• People with diabetes need a dilated eye exam at least once a year.
• Wear sunglasses that block UV light and safety glasses for risky work.
• Do not smoke; smoking raises the risk of cataracts and macular degeneration.
• Control blood pressure, blood sugar and cholesterol.
• Follow the 20-20-20 rule for screens: every 20 minutes, look at something 20 feet (6 m) away for 20 seconds.

Frequently asked questions

When should I worry about vision problems?

Worry about any sudden change: vision loss, a curtain or shadow, a burst of new floaters and flashes, sudden double vision, or a painful red eye with blurring. These need same-day or emergency care. Gradual blurring can be checked at a routine eye exam.

What causes sudden blurry vision?

Sudden blur can come from dry eye or high blood sugar, which are usually not urgent. It can also come from acute glaucoma, retinal detachment, stroke, optic neuritis or bleeding in the eye. If blurring does not clear with blinking, or comes with pain or other symptoms, get seen urgently.

Can stress cause vision problems?

Stress can cause eye strain, twitching and blurred vision from tiredness and dry eye. It is also linked with central serous chorioretinopathy, a fluid build-up under the retina. Persistent or sudden vision changes should not be put down to stress without an eye exam.

Can high blood pressure affect vision?

Yes. Long-term high blood pressure can damage retinal blood vessels (hypertensive retinopathy), and very high blood pressure can cause sudden blurring. It also raises the risk of retinal vein and artery blockages and stroke, which can cause sudden vision loss.