Vision loss can affect one or both eyes. Depending on the cause, a person may experience vision loss with dark, partial, or blurry vision.
Some forms of vision loss are temporary, while others are irreversible. In both cases, people can often take steps to improve or correct their vision.
Vision loss can occur suddenly or gradually over time. The best treatment will depend on the cause.
According to the Centers for Disease Control and Prevention (CDC), vision problems are among the top 10 disabilities in adults, and one of the most prevalent disabilities in children.
This article looks at symptoms and possible causes of vision loss in one eye. It also discusses potential treatments.
“Vision loss” is a term for losing the ability to see properly without requiring some form of intervention, such as glasses.
There are different types of vision loss with various causes:
- central vision loss, which affects the center of a person’s vision
- peripheral vision loss, which affects the edges of vision
- total vision loss
- night blindness, or trouble seeing in low light
- blurry, hazy, or out-of-focus vision
- difficulty seeing shapes or only seeing shadows
Other symptoms may also occur depending on the cause of vision loss.
Sudden vision loss occurs quickly, over a period of a few seconds or minutes to a few days. In the following sections, we discuss possible causes of sudden vision loss.
Common visual disturbances include:
- seeing zig-zag lines
- tunnel vision
- vision loss to the left or right side
- a complete loss of vision
Migraine auras typically last for 10–30 minutes or less than an hour. Some last just a few seconds. Avoiding bright lights and loud sounds and taking migraine medication can ease the symptoms.
A detached retina is when the retina lifts away from the back of the eye. It can cause total or partial loss of vision in the affected eye. When a person has a detached retina, it may appear that something is blocking part of their vision.
A detached retina is serious. If left untreated, it can lead to permanent vision loss. Treatment involves some form of surgery dependent on what a person’s doctor recommends.
A black eye occurs as a result of an injury to the eye and can affect a person’s vision.
“A black eye” is a term that refers to bruising around the eye, usually caused by impact to that area. Increased pressure inside the eyeball can occur from any swelling caused by a black eye. This in turn can lead to vision loss.
Sudden vision loss may also result from an injury to the eye. A corneal abrasion is a small scratch on the cornea, which is the clear window at the front of the eye.
Depending on how serious the injury is, corneal abrasions could be temporary or permanent, and treatment may vary accordingly.
Most corneal abrasions heal in 24–72 hours by themselves and without further complications. However, a person should seek medical attention immediately if there is something stuck in the eye.
In some cases, vision loss occurs gradually and can be more difficult to notice. For some people, this relates to aging. In other cases, it may stem from a medical condition.
Amblyopia, also known as lazy eye, is a type of poor vision that affects just one eye.
A breakdown in how the brain and the eye work together means that the brain does not translate images from one eye, and the child relies more on the other eye.
This causes the vision in the affected eye to worsen over time. Treatment may involve corrective devices, such as glasses, and in some cases, even surgery.
Wearing an eye patch over the stronger eye can help retrain the weaker eye.
A cataract is a cloudy area in the lens of the eye. Cataracts can be unilateral, affecting one eye, or bilateral, where they form in both eyes.
A cataract can make a person’s vision blurry, hazy, or less colorful. It often develops gradually, so many people are not aware that it is developing.
Cataracts are very common. According to the NEI, over half of all Americans aged 80 years or older either have cataracts or have had surgery to remove cataracts.
Eye surgery is the primary treatment for this eye condition.
The symptoms can be so gradual that a person may not know they have glaucoma until they have an eye examination. They may lose vision slowly, beginning with the peripheral vision. Glaucoma can occur in one or both eyes.
In the case of angle-closure glaucoma, the intraocular pressure can go up rapidly and cause pain, nausea, vomiting, or vision loss. Healthcare professionals typically treat it with eye drops. Sometimes, however, a laser or surgical procedure may be necessary.
Without treatment, glaucoma can eventually cause blindness. Prescription eye drops are the main treatment for glaucoma. By lowering the pressure in the eye, eye drops can prevent further damage to the optic nerve. However, they cannot reverse damage already caused.
A person should seek immediate medical attention if any of the following co-occurs with symptoms of vision loss:
- severe headache
- difficulty speaking
- facial drooping
- loss of muscle control on one side of the body
- severe eye pain
These could be signs of a stroke or another serious medical condition.
Typically, vision loss is not a consequence of natural aging of the eye. Vision loss is usually the result of an eye condition, injury to the eye, or both.
Loss of vision is not always permanent. In many cases, people can treat or correct their vision loss.
The American Foundation for the Blind provide some resources to help people manage new vision loss.