Refractive errors are the most common type of eye disorders. They occur when the shape of the eye does not bend light correctly, which keeps the light rays from focusing properly on your retina. The result is blurred vision.
Refractive error, also known as refraction error, is a problem with focusing light accurately on the retina due to the shape of the eye. The most common types of refractive error are near-sightedness, far-sightedness, astigmatism, and presbyopia. Near-sightedness results in faraway objects being blurry, far-sightedness and presbyopia result in close objects being blurry, and astigmatism causes objects to appear stretched out or blurry. Other symptoms may include double vision, headaches, and eye strain.
What signs and symptoms may I have with different types of refractive errors?
The most common symptom is blurry vision. You may rub, shut, or cover one eye, squint, or tilt or turn your head often. You may also have eye strain, headache, or fatigue. You may have other symptoms based on your type of refractive error:
People with a simple astigmatic refractive error see contours of a particular orientation as blurred, but see contours with orientations at right angles as clear. When one has a cylindrical error, one has astigmatism.
When the optics are too powerful for the length of the eyeball one has myopia or nearsightedness.
Hyperopia or Farsightedness
This can arise from a cornea with not enough curvature or an eyeball that is too short.
COMMON REFRACTIVE ERRORS & CONDITIONS INCLUDE
How are refractive errors diagnosed?
Your healthcare provider may ask about your symptoms, medical history, and medicines. He or she may do a series of tests that aim bright lights directly at your eyes. You may also need any of the following tests:
A cover-uncover test checks if your eyes are aligned
An object is placed at a certain distance far away from you while one eye is covered. Your healthcare provider carefully looks at the uncovered eye for any movement.
A test for fixation checks how well your uncovered eye follows the light
One eye is covered while your healthcare provider moves a small flashlight in front of you. He or she repeats the test on the other eye and compares the results.
A refraction test checks the lens of your eyes
You will be asked to look at a chart through a device that has lenses of different strengths. You will be asked if the word or picture is clear as he or she changes the lenses.
A visual acuity test checks your ability to see clearly
You will be shown charts with letters, pictures, and shapes. Your healthcare provider may ask you to read eye charts placed farther down the room from you. These charts help your healthcare provider check how well you see colors and lines at different distances.
How are refractive errors treated?
Contact lenses and glasses help correct the shape of your eyes. This helps light to focus correctly and improves your vision.
You may need eye drops or ointments. These decrease inflammation, help your eyes focus and can make your eye muscles stronger.
You may need surgery to reshape the curve of your cornea. There are different types of refractive surgery to treat refractive errors. Your vision may be corrected by a laser. Your healthcare provider may place tiny plastic rings into the cornea. Ask your healthcare provider for more information on refractive surgery.
What can I do to care for my eyes?
Get regular eye exams. Get your eyes checked at least every year.
Eat healthy foods. Fresh fruits and vegetables that are rich in vitamins A and C may help with your vision. Foods such as sweet potatoes, apricots, and carrots are rich in good nutrients for the eyes.
Take care of your contacts or glasses. Store, clean, and use your contacts or glasses as directed. Replace your glasses or contact lenses as often as your healthcare provider suggests.
Decrease eye strain. Rest your eyes, especially after you read or sew for long periods of time. Get plenty of sleep at night. Use lights that reduce glare in your home, school, or workplace.
Wear dark sunglasses. This will help prevent pain and light sensitivity. Make sure the sunglasses have UVA and UVB protection. This will protect your eyes when you go outside.
Use eyedrops safely. If your treatment plan includes eyedrops, it is important to use them as directed. Your provider may give you detailed instructions to follow. The eye drops may also come with safety instructions. Follow all instructions to help prevent infection. Do not touch the tip of the bottle to your eye. Germs from your eye can spread to the medicine bottle.