Distorted Vision (Metamorphopsia)

What distorted vision is like

People describe:

• door frames, window blinds or lines of text that look wavy or kinked
• faces that look misshapen
• a bend or "dip" in a straight edge
• objects looking smaller (micropsia) or larger (macropsia, see image magnification) in the affected eye
• a blurred or missing patch in the center

Because the other eye fills in the gaps, many people only notice distortion when they cover one eye. That is why checking each eye separately matters.

Why the macula causes distortion

The macula is a small area about 5 mm across at the center of the retina, packed with cone cells for sharp, detailed and color vision. If the macula is lifted by fluid, wrinkled by scar tissue or stretched by a hole, the cells shift out of their normal positions. The brain still interprets signals as if the cells were in place, so the image looks bent.

Common causes of distorted vision

Age-related macular degeneration

The leading cause in people over 50. In the dry form, distortion and blurring develop slowly. The wet form, in which new leaky blood vessels grow under the macula, causes sudden distortion and a dark central patch. Wet age-related macular degeneration needs injections as soon as possible to save vision.

Epiretinal membrane

A thin layer of scar tissue grows on the surface of the macula and contracts, wrinkling it. It causes gradual distortion and blur, mainly in people over 50 or after eye surgery or inflammation. Mild epiretinal membranes are watched; troublesome ones are peeled in surgery.

Macular hole

A small full-thickness break in the macula, usually from the gel inside the eye pulling as it ages. It causes distortion and a central gap, often noticed when reading. Surgery closes most holes. See macular hole.

Central serous chorioretinopathy

Fluid collects under the retina, usually in one eye of men aged 25 to 50, often linked to stress or steroid use (including creams, inhalers and tablets). It causes blurred, dim, distorted vision and objects looking smaller. Most cases clear on their own within 3 to 4 months.

Diabetic macular edema and vein occlusion

Leaking vessels in diabetic macular edema, or a blocked retinal vein, cause swelling of the macula with blur and distortion.

Retinal detachment

When a detachment reaches the macula, central vision distorts or disappears. It is usually preceded by flashes, new floaters and a spreading shadow. Retinal detachment needs emergency surgery.

Migraine aura

Migraine aura can cause zigzag lines, shimmering, and warping of shapes in both eyes' field of view, lasting 5 to 60 minutes, often followed by headache. It fully resolves.

Other causes

• Severe astigmatism or keratoconus, which distort the image at the front of the eye
• High myopia with macular changes
• Inflammation in the eye (uveitis)
• Rarely, brain conditions such as stroke or seizures affecting the visual cortex

Clues to the cause

Checking at home with an Amsler grid

An Amsler grid is a square of evenly spaced lines with a central dot. To use it:

1. Wear your reading glasses and hold the grid about 35 cm (14 in) away in good light.
2. Cover one eye and look at the central dot.
3. Note any wavy, missing or blurred lines.
4. Repeat with the other eye.

People with macular degeneration are often advised to check daily. Any new change should be reported to your eye doctor promptly.

How eye doctors diagnose the cause

An optometrist or ophthalmologist will check vision in each eye, test with an Amsler grid, and examine the retina after dilating drops. The key test is optical coherence tomography (OCT), a quick, painless scan that shows the layers of the macula in cross-section and reveals fluid, membranes and holes. Fluorescein or OCT angiography may be used to look for leaking vessels.

Treatment

• Wet macular degeneration and macular edema: injections of anti-VEGF medicine into the eye, usually repeated every 4 to 16 weeks.
• Epiretinal membrane and macular hole: vitrectomy surgery to peel the membrane or close the hole.
• Central serous chorioretinopathy: stopping steroids where possible and observation; laser or photodynamic therapy for persistent cases.
• Retinal detachment: urgent surgery.
• Dry macular degeneration: specific vitamin and mineral supplements (AREDS2 formula) for intermediate disease, stopping smoking, and low vision aids. Injections to slow geographic atrophy are available in some countries.

Distortion often improves after successful treatment but may not disappear completely, especially if it was present for a long time.

Frequently asked questions

What causes straight lines to look wavy?

Wavy lines usually mean the macula, the center of the retina, has been distorted by fluid, scar tissue or a hole. Common causes are macular degeneration, epiretinal membrane, macular hole and central serous chorioretinopathy. See an eye doctor promptly for an OCT scan.

Is distorted vision an emergency?

Sudden distortion in one eye, especially with a dark spot, flashes, floaters or a spreading shadow, should be seen the same day or within 24 to 48 hours, because wet macular degeneration and retinal detachment respond best to fast treatment. Slow changes can be booked routinely.

Can stress cause distorted vision?

Stress is linked with central serous chorioretinopathy, where fluid collects under the retina and causes blurred, distorted vision in one eye. It also triggers migraine auras in some people. Distortion still needs an eye exam to rule out other causes.

Can glasses fix distorted vision?

Glasses correct distortion caused by astigmatism or other focusing errors, but not distortion from a damaged macula. If lines still look wavy with your correct glasses on, the cause is likely in the retina and needs an eye doctor's assessment.

What is metamorphopsia?

Metamorphopsia is the medical term for distorted vision, in which straight lines look curved or wavy and shapes look warped. It is a typical sign of disease affecting the macula and is tested with an Amsler grid.