Refractive Errors Of The Eye — All You Must Understand
Did you know approximately 12 million people 40 years and over in the United States have vision impairment of some or the other kind?
Refractive errors are types of vision impairment caused by irregularity in the eye shape. These vision problems occur because the shape of your eye prevents light from properly focusing on your retina.
Thus, making blurry images to appear, making it difficult to see objects clearly.
Who Is At Risk For Refractive Errors Of The Eye?
A growing amount of research has suggested that refractive errors are mostly inherited. That means they can get passed down from parents to their children. If you have family members who wear glasses or contact lenses, you are more likely to develop refractive errors in the eye.
Refractive errors in childhood are a common type of vision impairment. Studies suggest, the prevalence of refractive errors in children is around 47% for those between ages 11-15. But regardless of the age, refractive errors of the eye happen to anyone.
What Causes Refractive Errors In The Eye?
Refractive errors of vision are usually caused by the deformation of the eyeball. When the eyeball is too long or too short, it fails to properly form an image in the brain, leading to refractive errors in the eye.
Some other reasons include:
- Eye injuries
- Aging of the lens
- Other environmental factors.
Now, you know What are refractive errors of the eye and what causes them. Let’s understand their types and the treatment options available.
What Are The Four Common Refractive Errors Of The Eye:
For an object to be seen clearly, its light has to fall on the retina, a special tissue at the back of your eye. But, if the light falls anywhere else, it leads to the following 4 common refractive errors seen in the eye.
- Myopia
- Hyperopia
- Presbyopia
- Astigmatism
Myopia (or near-sightedness)
This condition causes far-away objects to appear blurry. Your vision will usually be fine in close proximity, but your ability to see far away objects will be poor.
Myopia Causes
This usually happens when your eyeball is longer than normal, which causes the light to focus incorrectly. Instead of focusing on the retina, the light gets focused in front of the retina, causing blurred vision.
Myopia Symptoms
Do you find yourself squinting when asked to read road signs? You probably should get yourself checked for Myopia.
Headaches and eye strain are also some of its common symptoms.
Hyperopia (or far-sightedness)
In hyperopia, you have trouble seeing things up close, whereas objects at a distance appear normally.
Hyperopia Causes
When your eyeball is shorter than it should be, it causes the image to form behind the retina, causing this condition.
Hyperopia Symptoms
You will have difficulty reading, threading a needle, and doing other up-close tasks due to this condition.
Presbyopia (or age-related farsightedness)
Presbyopia refers to the inescapable, gradual loss of the ability to see items up close as you get older.
Presbyopia Causes
In younger individuals, the eye lens is quite flexible and soft. This makes it easier to focus light on the retina to make you see things clearly. But with age, the lenses gradually lose their flexibility causing the light to focus behind the retina instead of on it.
Presbyopia Symptoms
You may have Presbyopia if you have trouble seeing up-close things and you’re older than 40.
Astigmatism
Astigmatism is a type of error that causes distorted vision at all distances.
Astigmatism Causes
This condition occurs when your eyeball is egg-shaped instead of round. This distorted shape causes the light to get bent more in one direction and less in the other. When this happens, only a part of the object is in focus, and objects may appear blurry and wavy.
Astigmatism Symptoms
You may experience headaches and eyestrain while looking at things at all distances.
How Are Refracted Errors In The Eye Diagnosed?
As you can see, the symptoms for each refractive error are somewhat similar. You should schedule an appointment with your ophthalmologist if you exhibit any of the symptoms listed above.
The ophthalmologist will correctly determine the type of refractive error by performing a comprehensive eye examination. This involves a Snellen chart which is a chart with a series of letters of varying sizes on it.
You have to read the letters until they become too small for you to read. Based on this, the doctor will conclude whether or not you have refractive errors or the type of refractive error you’re suffering from.
These tests are quick, simple, and painless.
Refractive Errors And Their Correction — Treatment Options
Refractive errors, if left untreated, can lead to more serious eye conditions or in some cases, complete blindness. There are many options available today to improve the condition. Pick any of them, and you’re good to go:
Glasses
Eyeglasses function by bending light correctly on the retina. Hence, making your vision clear. There are many types of eyeglass lenses available to correct the different refractive errors associated with the cornea, lens, or shape of the eye.
Besides, they are the most inexpensive and simple way to correct vision impairment. Based on the refractive error, these include
Reading Glasses
Reading glasses can help people suffering from Presbyopia see things clearly up-close. You can also buy them without a prescription.
Single vision glasses
Single vision glasses can correct either Myopia or Hyperopia but not both.
Bifocals glasses
Bifocal glasses are usually prescribed for Presbyopia patients with an additional error. That may be Myopia, Hyperopia, or Astigmatism.
Varifocals/Progressive lenses
These are a better option than Trifocals as they do not have any lines separating the near and distance vision.
Contact lenses
Contact lenses are artificial lenses that cover your cornea, helping you see things clearly. If you’re not a big fan of wearing glasses, you can go for contact lenses that are as effective as eyeglasses.
There are several options available.
Hard Contact Lenses
They are usually made of Rigid Gas-Permeable (RGP) lenses. One of the advantages of hard contact lenses is that they are very unlikely to tear.
Soft Hydrophilic Contact Lenses
Soft contact lenses are easier to wear and are more comfortable than hard ones. These include types like Daily wear, Extended wear, Toric and tinted lenses.
What are the benefits of wearing contact lenses?
- They are easier to wear.
- They do not fog up like eyeglasses.
What are the risk factors associated with wearing contact lenses?
Contact lenses are a great option only if you use them correctly. Make sure you disinfect your lenses before and after every use to avoid any other eye problems.
It is also essential to take out your lenses before hopping into the shower as it may cause eye irritation.
Laser treatment for refractive errors
If you’re not a big fan of wearing glasses or contact lenses, you can go for this option. There are many types of surgeries to correct refractive errors in the eye.
LASIK
Laser-Assisted In Situ Keratomileusis (LASIK) is the most common type of refractive surgery. A strong beam of light or laser focuses just underneath the corneal flap to change its shape, making your vision clear. The surgery can help to correct Myopia, Hyperopia, and Astigmatism.
Photorefractive Keratectomy (PRK)
This procedure can help treat Myopia. It works the same way as LASIK, but instead of the corneal flap, the laser gets focused on the surface of the cornea.
Astigmatic Keratotomy (AK)
As the name suggests, it helps to correct astigmatism. People with astigmatism have an egg-shaped cornea. AK works by creating incisions that relax the cornea, thus returning the shape back to normal. It is a safe and effective way to correct astigmatism.
Conductive Keratoplasty (CK)
CK is a non-invasive method of treating refractive errors in the eye. It is mostly performed to correct Hyperopia. The surgical procedures mentioned above use lasers to correct the condition. Some patients, however, may not be ready for such invasive surgeries. For these patients, CK is an effective and safe option.
Remember these tips:
- Ask your eye care provider if surgery is a good option for your particular vision problem.
- Make regular visits to your doctor to prevent the condition from getting worse.
- If refractive errors run in your family, get your eyes examined as soon as possible.
Summing Up
Hope you got your answers about what are refractive errors, the causes, and their symptoms. We also shared with you the 4 common types of refractive errors in the eyes and how they can get treated.
You have several options like glasses, contact lenses, and LASIK surgeries to help treat your eyes.
So, even though there is no permanent cure available for refractive errors, you don’t have to live your life in misery. Taking necessary measures as soon as you notice the symptoms mentioned above can help mitigate refractive errors of the eye.
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