5 Things To Know About Astigmatism
Astigmatism is a refractive condition that causes blurred or distorted vision. Astigmatism is more common than either nearsightedness or farsightedness. It is, however, common to have both astigmatism and either nearsightedness or farsightedness. When the eye focuses light, it should come to a single point on the retina. With astigmatism, light focuses on two different points rather than just one point on the retina. The brain interprets the two points as a blurred line instead of a single point. Astigmatism may not cause enough symptoms to warrant any correction, but if the astigmatism is high enough amount, it can be corrected with glasses or contact lenses.
The Focusing System of the Eye
The eye has a multi-part focusing system that allows clear vision. The focus begins with the cornea on the front of the eye.
The cornea is the biggest component of the focusing system and it bends light into the eye through the pupil in the iris.
Behind the iris, the crystalline lens again bends light and should create a single point exactly on the retina in the back of the eye.
The retina is the “screen” of the focusing system. Light focuses on the retina in order to send signals to the brain and create vision.
Where Astigmatism Occurs
Astigmatism can occur in either the cornea or the crystalline lens. Most of the time, if there is a large amount of astigmatism, it is due to the shape of the cornea.
The cornea should be completely round and spherical, however, it can be steeper in one direction and flatter in the other creating astigmatism.
The crystalline lens can also create small amounts of astigmatism by having unequal focusing of light.
Symptoms of Astigmatism
Astigmatism will impact vision at all distances and may lead to blurry vision, shadows on letters, or halos with lights.
Since the eye is perceiving a line in place of a point, lights will be stretched out and may seem to smear or have a starburst.
These symptoms are usually worse at night when lights are more apparent, and the pupil is larger.
Astigmatism may also cause headaches or eye strain if it is not corrected and causes issues with focusing or reading.
How Astigmatism is Corrected
To correct astigmatism, glasses or contact lenses can be worn. Depending on the amount of astigmatism, contact lenses may not be a viable option.
Glasses allow the best, most specific correction for astigmatism as the lenses can be ordered with the exact power needed.
If there are irregular or high amounts of astigmatism, specialty contact lenses are an option. These lenses are rigid and alter the refraction by creating a smooth surface for the front of the eye.
Diagnosing Astigmatism
At a routine eye examination, the eye doctor will perform a refraction to assess the need for glasses or contact lenses.
In the refraction, astigmatism will be evaluated and diagnosed if present.
Our eye doctors at GHEye excel in the prescription of glasses, contact lenses and the diagnosis of a variety of eye diseases. Call our optometrists at (571) 445-3692 to schedule your appointment today to be evaluated for astigmatism. Our eye doctors, Dr. Ally Stoeger and Dr. Jennifer Sun, provide the highest quality optometry services and eye exams in the Gainesville VA and Haymarket VA areas.
Astigmatism is a refractive condition that causes blurred or distorted vision. Astigmatism is more common than either nearsightedness or farsightedness. It is, however, common to have both astigmatism and either nearsightedness or farsightedness. When the eye focuses light, it should come to a single point on the retina. With astigmatism, light focuses on two different points rather than just one point on the retina. The brain interprets the two points as a blurred line instead of a single point. Astigmatism may not cause enough symptoms to warrant any correction, but if the astigmatism is high enough amount, it can be corrected with glasses or contact lenses.
The Focusing System of the Eye
The eye has a multi-part focusing system that allows clear vision. The focus begins with the cornea on the front of the eye.
The cornea is the biggest component of the focusing system and it bends light into the eye through the pupil in the iris.
Behind the iris, the crystalline lens again bends light and should create a single point exactly on the retina in the back of the eye.
The retina is the “screen” of the focusing system. Light focuses on the retina in order to send signals to the brain and create vision.
Where Astigmatism Occurs
Astigmatism can occur in either the cornea or the crystalline lens. Most of the time, if there is a large amount of astigmatism, it is due to the shape of the cornea.
The cornea should be completely round and spherical, however, it can be steeper in one direction and flatter in the other creating astigmatism.
The crystalline lens can also create small amounts of astigmatism by having unequal focusing of light.
Symptoms of Astigmatism
Astigmatism will impact vision at all distances and may lead to blurry vision, shadows on letters, or halos with lights.
Since the eye is perceiving a line in place of a point, lights will be stretched out and may seem to smear or have a starburst.
These symptoms are usually worse at night when lights are more apparent, and the pupil is larger.
Astigmatism may also cause headaches or eye strain if it is not corrected and causes issues with focusing or reading.
How Astigmatism is Corrected
To correct astigmatism, glasses or contact lenses can be worn. Depending on the amount of astigmatism, contact lenses may not be a viable option.
Glasses allow the best, most specific correction for astigmatism as the lenses can be ordered with the exact power needed.
If there are irregular or high amounts of astigmatism, specialty contact lenses are an option. These lenses are rigid and alter the refraction by creating a smooth surface for the front of the eye.
Diagnosing Astigmatism
At a routine eye examination, the eye doctor will perform a refraction to assess the need for glasses or contact lenses.
In the refraction, astigmatism will be evaluated and diagnosed if present.