What Are Refractive Errors?
occur when the shape of the eye prevents light from focusing directly on the
retina. The length of the eyeball (longer or shorter), changes in the shape of
the cornea, or aging of the lens can cause refractive errors.
Refraction is the
bending of light as it passes through one object to another. Vision occurs when
light rays are bent (refracted) as they pass through the cornea and the lens.
The light is then focused on the retina. The retina converts the light-rays
into messages that are sent through the optic nerve to the brain. The brain
interprets these messages into the images we see.
What are the different
types of Refractive Errors?
The most common
types of refractive errors are myopia, hyperopia, presbyopia,
Myopia (nearsightedness) is a condition where objects
up close appear clearly, while objects far away appear blurry. With myopia,
light comes to focus in front of the retina instead of on the retina.
Hyperopia (farsightedness) is a common type of
refractive error where distant objects may be seen more clearly than objects
that are near. However, people experience hyperopia differently. Some people
may not notice any problems with their vision, especially when they are young.
For people with significant hyperopia, vision can be blurry for objects at any
distance, near or far.
Astigmatism is a condition in which the eye does not focus
light evenly onto the retina, the light-sensitive tissue at the back of the
eye. This can cause images to appear blurry and stretched out.
Presbyopia is an age-related condition in which the
ability to focus up close becomes more difficult. As the eye ages, the lens can
no longer change shape enough to allow the eye to focus close
How are refractive
An eye care
professional can diagnose refractive errors during a comprehensive dilated eye examination.
People with a refractive error often visit their eye care professional with
complaints of visual discomfort or blurred vision. However, some people don’t
know they aren’t seeing as clearly as they could.
Who is at risk for Refractive Errors?
most adults over age 35. Other refractive errors can affect both children and
adults. Individuals that have parents with certain refractive errors may be
more likely to get one or more refractive errors.
What are the signs and
symptoms of Refractive Errors?
Blurred vision is
the most common symptom of refractive errors. Other symptoms may include:
- Double vision
- Glare or
halos around bright lights
- Eye strain
How are refractive
can be corrected with eyeglasses, contact lenses, or surgery.
Eyeglasses are the simplest and safest way to correct
refractive errors. Your eye care professional can prescribe appropriate lenses
to correct your refractive error and give you optimal vision.
Lenses work by
becoming the first refractive surface for light rays entering the eye, causing
a more precise refraction or focus. In many cases, contact lenses provide
clearer vision, a wider field of vision, and greater comfort. They are a safe
and effective option if fitted and used properly. It is very important to wash
your hands and clean your lenses as instructed in order to reduce the risk
If you have certain
eye conditions you may not be able to wear contact lenses. Discuss this with
your eye care professional.
Refractive Surgery aims to change the shape of the cornea
permanently. This change in eye shape restores the focusing power of the eye by
allowing the light rays to focus precisely on the retina for improved vision.
There are many types of refractive surgeries. Your eye care professional can
help you decide if surgery is an option for you.