Peripheral Vision Loss (Loss of Side Vision)

How peripheral vision works

Each eye sees about 150 to 180 degrees side to side when you look straight ahead. Central vision, used for reading and faces, comes from the macula. Peripheral vision comes from the rest of the retina and is especially good at detecting motion and seeing in low light. Signals travel through the optic nerves, cross partly at the optic chiasm behind the eyes, and continue to the visual cortex at the back of the brain.

Where along this route damage happens produces a characteristic pattern of loss.

Patterns of side vision loss

Causes of peripheral vision loss

Glaucoma

Glaucoma is the leading cause. Damage to the optic nerve, often with raised eye pressure, causes gradual, painless loss that begins in the mid-periphery. Central vision is spared until late, so many people do not notice it until significant vision is lost. Risk is higher over 60, with a family history, in people of African, Hispanic or Asian descent, and with high myopia, diabetes or long-term steroid use. Lost vision cannot be restored, so early detection matters.

Retinal detachment

In retinal detachment, the retina peels away from the back of the eye. It typically starts with a burst of floaters and flashing lights, then a shadow or curtain moving in from the side. It needs surgery within hours to days to save vision.

Stroke

A stroke affecting the visual pathways at the back of the brain causes loss of the same side of vision in both eyes (homonymous hemianopia). People often think only one eye is affected. Read with each eye covered in turn to check.

Pituitary tumor

A tumor of the pituitary gland pressing on the optic chiasm causes loss of the outer fields in both eyes (bitemporal hemianopia), along with hormonal symptoms. See pituitary tumor.

Retinitis pigmentosa

Retinitis pigmentosa is an inherited disease of the rod cells that begins with night blindness in childhood or young adulthood and slowly narrows vision to a tunnel.

Other causes

• Optic neuritis, often with eye pain and dim color vision
• Ischemic optic neuropathy and giant cell arteritis in older adults
• Retinal artery or vein occlusion
• Brain tumors and head injury
• Medicines such as vigabatrin and hydroxychloroquine (at high cumulative doses)
• Advanced diabetic retinopathy and laser treatment scars

Temporary tunnel vision

Brief narrowing of vision can occur with migraine aura, just before fainting, with a sudden drop in blood pressure, during panic attacks, and with low blood oxygen. It resolves in minutes. Repeated episodes need checking.

How it is diagnosed

• Confrontation testing: the examiner checks whether you can see fingers moving in each quarter of your vision.
• Automated visual field test (perimetry): you press a button when you see lights flash in different positions. It maps blind areas precisely.
• Eye pressure measurement and examination of the optic nerve.
• Dilated retinal exam and optical coherence tomography (OCT) scans of the nerve and retina.
• MRI of the brain for chiasm or brain pathway patterns.
• Genetic testing and electroretinography for suspected inherited retinal disease.

Treatment

• Glaucoma: pressure-lowering eye drops, laser treatment or surgery to prevent further loss.
• Retinal detachment: urgent laser, freezing treatment, gas bubble injection or surgery.
• Stroke: emergency treatment, then rehabilitation. Some vision may recover over months.
• Pituitary tumor: medicine or surgery, which often improves vision.
• Retinitis pigmentosa: gene therapy for specific gene types, low-vision aids and orientation training.

Living with field loss

Low-vision services teach scanning techniques, use prisms and offer mobility training. Many US states and other countries have minimum visual field requirements for driving, so ask your eye doctor whether you are safe and legal to drive.

Frequently asked questions

What causes sudden loss of peripheral vision?

The most common urgent causes are retinal detachment, which often follows flashes and floaters, and stroke, which affects the same side of vision in both eyes. Acute glaucoma and blocked retinal blood vessels are other causes. All need emergency care.

Can peripheral vision loss be restored?

It depends on the cause. Vision lost to glaucoma is permanent, but treatment prevents more loss. Vision often improves after prompt retinal detachment repair or pituitary tumor treatment, and partly after some strokes.

What does peripheral vision loss in one eye mean?

Loss in only one eye points to a problem in that eye or its optic nerve, such as glaucoma, retinal detachment, optic neuritis or a blocked retinal vessel. Test by covering each eye in turn and see an eye doctor promptly.

How do I know if I am losing peripheral vision?

Signs include bumping into objects at your sides, tripping, missing people approaching from the side, or difficulty driving and in the dark. Gradual loss is easily missed, so regular eye exams with pressure checks are the best way to catch glaucoma early.

Can anxiety cause tunnel vision?

During a panic attack, some people briefly experience narrowed vision along with dizziness and a racing heart. It passes within minutes. Persistent or recurrent tunnel vision should always be examined by an eye doctor.