Astigmatism Correction: What Is It and How It Works

Astigmatism Correction: What Is It and How It Works

Astigmatism is an extremely common problem. Over 1 in 4 American children between the ages of 5 and 17 develop or deal with symptoms of astigmatism. Even some adults that had no childhood issues develop astigmatism later on, sometimes as a result of an eye injury.

But what exactly is wrong with an astigmatic eye, and how can you resolve the symptoms?

What is astigmatism?

Astigmatism is classified as a refractive disorder. This means that it, like other eye disorders, causes the eye to improperly and unevenly reflect light that hits the retina, which is the tissue at the back of the eye that “reads” what you see.

When light bends while passing through an object, it is called refraction. Light that passes through the outer layer of the eye is refracted into the interior of the eye.

When you see something, what is actually occurring is that light rays are bent, or refracted, by the cornea and lens, then focused onto the retina in the back of the eye. The retina translates those light rays into information that your brain can read and transmitted up the optic nerve.

When the brain interprets that information, you are able to see. It’s a very fast process, so we’re entirely unaware that there is a delay between the light hitting and our experience of seeing!

Astigmatism usually occurs because the cornea has an irregular shape or has been injured or scratched up. Instead of focusing the light  on the retina, it generates multiple focus points, or the focused light hits in the wrong area of the eye.

This produces experiences of blurred and distorted vision. Common symptoms include headaches, blurred vision, or constant squinting. Interestingly, we squint because it creates pressure on the eye which can temporarily reshape the cornea, actually changing the function of the lens!

Astigmatism comes in a couple different forms. Myopic astigmatism is generally known as nearsightedness, and hyperopic astigmatism is usually called farsightedness. If one eye has nearsightedness and the other farsightedness, that’s known as mixed astigmatism.

How can I know if I have astigmatism?

Luckily, there’s a very easy path to discover if you’re suffering from astigmatism. First, the symptoms are usually fairly obvious. If you begin to experience eye strain and headaches, especially after prolonged visual tasks like reading or typing, or find yourself squinting a lot, it’s worth seeing an optometrist or ophthalmologist to find out if something is wrong.

Either an optometrist or an ophthalmologist will discover astigmatism through the course of a routine eye exam. Some eye doctors choose to evaluate patients by shining a light into the patient’s eye and placing lenses in front of their eyes.

Others choose to use an automated refraction instrument that gives a quick preliminary assessment of the eye’s health. If anything anomalous is found during those steps, the eye doctor will then perform a manual refraction test to get specific results for your eye.

This is an entirely painless procedure, and you may have even had one done before. A complex instrument will be placed in front of you, and you’ll look through two eyeholes. A series of lenses will be switched in front of your eyes and you’ll be asked to compare specific lenses and tell the doctor which lens provides the clearest image.

You’ll be looking at an eye chart through this device and asked which of two lenses is the best as the doctor narrows down your best options. This test is also used to get a prescription for eyeglasses, should you choose to purchase them.

Astigmatism Correction

What options are there for astigmatism correction?

 

An excellent question. Astigmatism correction is generally reducible to three major options, and we’ll talk about them one at a time and examine their pros and cons.

Astigmatism Correction pros and cons #1: Eyeglasses

The first solution that everybody thinks of is, of course, eyeglasses. Instead of treating the cause of astigmatism, eyeglasses essentially add an extra outer layer to your eye. Glasses are dependable, often the least expensive option, are easy to take care of, and are unlikely to cause side effects (outside some initial headaches, perhaps), simply because they never touch the eye itself. Even better, glasses are modular and can be replaced if your prescription changes.

However, glasses are also a big change in how you look, and add an extra item to keep track of. Some professions aren’t well-suited to glasses (like professional athletics, or firefighting), though there are sometimes semi-expensive solutions to those issues, like prescription goggles.

If you find glasses inconvenient, annoying, or unattractive, you may want something less obtrusive. Finally, eyeglasses can be broken or lost, so if you prefer to deal with your eyecare once a day or less, you might prefer another option.

Astigmatism Correction pros and cons #2: Contact Lenses

Contact lenses operate in the same way that glasses do, but are placed on the surface of the eye. This means that contact lenses are much better for your peripheral vision. Contact lenses are also much less obtrusive than glasses, but they have a price tag to match. A wide range of lenses have also been designed to cater to individual needs, and you’ll only need to worry about contact lenses twice a day.

However, cleaning, maintaining, inserting, and removing contact lenses is a skill you’ll need to develop. If you do this wrong, you could accidentally cause corneal damage, and lenses can be easily lost. Contact lens costs vary, but expect to spend at least $150 on the lenses a year even if you don’t experience a prescription change or have to replace the lenses, and not counting the cleaning solution.

Astigmatism Correction pros and cons #3: Laser Vision Corrective Surgery

Laser Vision surgeries like PRK, LASIK, or Zeiss ReLEx SMILE are capable of full and permanent astigmatism correction. Since astigmatism is caused by an irregularly-shaped cornea, laser technology can fix it by reshaping the cornea into a better shape. Mild astigmatism can be easily cleared up by a single treatment, but severe cases might require multiple procedures.

The initial investment of LASIK surgery is more than a single pair of glasses or a set of contact lenses. However, the lifetime cost of eye care with eyeglasses or contact lenses exceeds the cost of the surgery sooner rather than later, so it should be considered a long-term investment that ultimately saves you money.

LASIK can be unsuitable for older patients, whose vision issues might have emerged from issues with the lens instead of the cornea. Some rarely occurring side effects like dry eye and halos have been linked to LASIK, but advanced technology is on the market that both reduces the chance of those side effects or is designed to clear up unintended side effects.

In any case, you’ll want to receive a consultation and find out whether LASIK is a real option for you, and whether any additional health problems might make side effects more likely for your case.