Peripheral vision is the ability to see what is to the sides without turning your head. It allows people to walk, drive, and avoid collisions with others or objects around them.

When this field of vision narrows, individuals can only see what is directly in front of them, as if looking through a tunnel. This condition is called peripheral vision loss, or tunnel vision. It is not a disease itself, but a symptom of many eye or nervous system disorders.

Retinal detachment is an ophthalmic emergency. When the retina separates from the tissue layer at the back of the eye, individuals may experience sudden peripheral vision loss. Without timely treatment, retinal detachment can lead to complete vision loss.

Glaucoma occurs when increased pressure inside the eye damages the optic nerve, which transmits signals from the eye to the brain. In its early stages, the disease often has no noticeable symptoms. As glaucoma progresses, individuals develop blind spots in their peripheral vision, and without treatment, the field of vision will continue to narrow, potentially leading to permanent vision loss.

A stroke occurs when blood flow to the brain is interrupted or a blood vessel in the brain ruptures. If the brain region processing vision is damaged, individuals may lose a portion of their visual field, including peripheral vision. This condition often affects both eyes and can be long-lasting.

Retinitis pigmentosa (RP) is a group of inherited diseases causing progressive retinal degeneration. The condition damages photoreceptor cells, particularly rod cells, which help with vision in low light and are responsible for peripheral vision.

The initial symptom is often night blindness, or difficulty seeing in the dark. Over time, the side vision gradually narrows, leaving individuals able to see only the central area. Some cases may lead to complete vision loss.

Peripheral vision helps a person observe what is happening on both sides without turning their head. *Image created by AI*.

Persistently high blood sugar can damage retinal blood vessels, leading to fluid leakage or hemorrhage. This complication causes blurred vision, reduced visual acuity, and can result in gradual peripheral vision loss if left untreated.

Optic neuritis disrupts the transmission of signals from the eye to the brain, causing vision impairment and potentially leading to peripheral vision loss. If not linked to another condition, optic neuritis can sometimes improve on its own. However, many cases are an early sign of multiple sclerosis or caused by infection, requiring treatment of the underlying cause.

Some individuals with migraine may experience visual disturbances before or during an attack, including tunnel vision. Unlike many other causes, this symptom typically lasts only 5 to 60 minutes and then resolves on its own.

The most important step is to identify and treat the underlying cause to prevent progressive vision loss. If symptoms are related to migraine, affected individuals should avoid triggers. In other cases, a specialist eye examination is recommended immediately upon noticing a narrowed field of vision or peripheral vision loss, especially if symptoms appear suddenly.

Bao Bao (Compiled)