Scotoma (Blind Spot): What Is It and How Can It Affect Your Vision?

Have you ever noticed a small area in your vision that seems blurry, dark, missing, or distorted? An area of reduced or missing vision within your visual field is called a scotoma. It is commonly described as a blind spot.

The term "blind spot" can sometimes be confusing because everyone has a normal blind spot in each eye. This natural blind spot occurs where the optic nerve leaves the eye. There are no light-sensitive cells at this location, so there is a small area where the eye does not detect visual information.

Most people never notice their normal blind spot because the brain fills in the missing information and because the two eyes work together.

An abnormal scotoma is different. It is an area of reduced or missing vision that results from a problem affecting the eye or visual system.

What Does a Scotoma Look Like?

A scotoma does not always appear as a completely black spot.

Depending on its location and cause, a person may describe a scotoma as:

• A blurry area

• A gray or dark spot

• A blank area

• A missing portion of an image

• Distorted or wavy vision

• An area where letters seem to disappear while reading

• Difficulty seeing details in a particular part of the visual field

Some scotomas are very noticeable, while others may be subtle.

The location of the scotoma also matters. A person may have a blind spot in the center of their vision, toward the side of their vision, or in another part of the visual field.

Central Scotoma vs. Peripheral Scotoma

A central scotoma affects the central portion of vision. This can be especially disruptive because central vision is important for detailed tasks.

People with central vision loss may have difficulty reading, recognizing faces, watching television, seeing details, or performing close-up work.  They may notice that when they look directly at something, part of the object seems missing or unclear.

A peripheral scotoma, on the other hand, affects vision away from the center.

Peripheral vision is important for awareness of the environment. A person with peripheral visual field loss may have difficulty noticing objects approaching from the side or may need to use deliberate scanning strategies when moving through unfamiliar environments.

The effect of a scotoma depends on its size, location, cause, and whether it affects one or both eyes.

What Causes a Scotoma?

There are many possible causes of an abnormal blind spot.

Conditions affecting the retina or macula can cause areas of missing or distorted central vision. Macular degeneration, for example, can affect the part of the retina responsible for detailed central vision.

Other eye conditions, including glaucoma and certain retinal diseases, can cause areas of visual field loss.  Problems involving the optic nerve or visual pathways can also result in changes in the visual field. In some cases, visual field loss can be associated with neurological conditions or injuries.

Because there are many possible causes, a new blind spot should not simply be assumed to be a normal part of aging.

How Can a Scotoma Affect Everyday Life?

Even a relatively small area of vision loss can have a major effect on everyday activities.

Reading is a good example. A person may be able to see the page but notice that certain letters or words seem to disappear. They may have to move their eyes or head to find the words they are trying to read.

A central scotoma can also make recognizing faces difficult. You may recognize that someone is standing in front of you but have difficulty seeing the person's facial features.

Peripheral vision loss can create different challenges. You may bump into objects, miss things that are beside you, or feel less confident navigating busy or unfamiliar environments.

These changes can lead people to stop participating in activities they previously enjoyed.

How Can a Low Vision Optometrist Help?

If a scotoma or other type of vision loss is affecting your daily activities, a low vision optometrist can help evaluate how you are using your remaining vision.

A low vision evaluation may include testing of visual acuity, visual fields, contrast, near vision, and other aspects of visual function.  The doctor will also want to understand what you are trying to accomplish in your daily life.

For example, if reading is important to you, the evaluation can focus on ways to make reading more manageable. If recognizing faces is your biggest concern, different strategies may be considered. If mobility or navigating your environment is difficult, the recommendations may focus on visual awareness and safety.

Can Low Vision Rehabilitation Help?

Although low vision rehabilitation cannot necessarily restore damaged vision, it can help you learn how to use your remaining vision more effectively.

Depending on the type and location of your vision loss, options may include magnification, specialized optical devices, electronic magnification, improved lighting, contrast enhancement, or changes to the way you approach certain visual tasks.

Some people with central vision loss can learn to use a different area of their remaining vision for specific activities. Others may benefit from techniques designed to improve awareness of their peripheral vision and scanning techniques.

The goal is not simply to provide a device. The goal is to find practical solutions that work in your everyday life.

You May Have More Options Than You Think

Living with a scotoma or other form of vision loss can be frustrating. You may find yourself changing the way you read, work, use technology, or interact with the world around you.

But vision loss does not necessarily mean giving up the activities that are important to you.

A low vision optometrist can help you understand your remaining visual abilities and explore options through low vision rehabilitation. With the right combination of technology, optical devices, environmental changes, and new techniques, many people can continue participating in activities that are meaningful to them.

If you have noticed a blind spot, missing area, or other persistent change in your vision, don't ignore it. An appropriate eye examination can help determine what is causing the change and whether low vision services may be helpful.