What are Blind Spots?
Vision is produced when light enters the eye and is focused on the retina which has photoreceptors (rods or cones). The retina is comprised of light-sensitive cells which conveys messages to your brain about what you visualize.
A blind spot, also known as a scotoma, is a naturally occurring phenomenon in each eye. It is an area or spot in the retina where the optic nerve connects. In this area, there is a lack of light-sensitive cells, hence this section of your retina is unable to visualize and is referred to as a blind spot.
A blind spot can also be artificial in nature. This occurs when there is interruption of light from reaching the photoreceptors (rods and cones) or when there is a local adaptation of the retina after visualizing a bright light.
Causes of Blind Spots
There is a tiny functional blind spot in every eye about the size of a pinhead. This tiny area, where the optic nerve travels via the surface of the retina, does not have photoreceptors. As there are no photoreceptors to sense the light, a blind spot is created. The absence of photoreceptors prevents the eye from conveying any information about the image we see to the brain, which normally interprets the image for us.
Some of the conditions that can cause blind spots include:
- Retinal detachment
- Macular degeneration
Symptoms of Blind Spots
Some of the common symptoms of blind spots include:
- Difficulty in perceiving certain colours
- A particular point in your vision that could be very light, blurred, dark, or flickering
- The requirement of bright light to see objects clearly
Diagnosis of Blind Spots
Your eye care provider will review your medical history and symptoms and conduct tests and exams, including:
- An exam utilizing eye drops to dilate or enlarge your pupils and a light to visualize the back of your eyes
- A slit lamp exam that involves a microscope with a light attached to closely observe the front and back of the eye
- A visual field test that employs spots of light to assess your central vision and your ability to visualize objects on all sides
Management of Blind Spots
Some of the measures that can be employed to manage symptoms of blind spots include:
- Use of filters to reduce computer screen glare
- Use of large-numbered keypads on phones and watch faces
- Use of large word sizes in an eReader and large size printed books
- Magnifying eyeglasses
- Customized computers with illuminated keyboards
- Use of AI (artificial intelligence) to read printed material aloud in a computer voice