Have you noticed changes in your vision lately? These could be caused by refractive eye errors. Refractive errors such as nearsightedness, farsightedness and astigmatism are some of the most common visual problems affecting both adults and children. Astigmatism is the less common error and acts differently than other refractive errors. Find out what causes astigmatism, how you are diagnosed for this eye condition and the simple measures we take to make your vision clear once more!
You may not have heard of the term “refractive error” before, but we bet you’ve heard of terms such as “nearsightedness”, “farsightedness” and “astigmatism”. These terms all describe refractive errors of the eyes. A refractive error isn’t a disease, but more of a malfunction in your eye that hinders your ability to see clearly. Millions of people have these types of errors, so they are very common in our patients and also very easily fixed.
A refractive error is when light does not focus correctly on the retina—or the light-sensitive area of the eye that tells your brain what you are seeing. Light will either focus before it reaches your retina, or it will focus behind it or at two different places. All of these malfunctions will lead to blurry vision.
Your vision is determined by how light hits various tissues of your eye. When you look at objects, light from those objects hits your eye, passing through your cornea, lens, pupil and other tissues until it hits your retina tissue. This is at the back of your eye and is connected to your optic nerve. The optic nerve receives information from light, then sends it to your brain through this nerve, and that is how you interpret images.
If that light focuses before your retina tissue, you have nearsightedness. If it focuses past the retina, you get farsightedness. Nearsightedness is when objects up close appear clearly, but objects farther away are blurry. The opposite is true for farsightedness. Objects far away appear clearly, while objects up close are blurry. Around 34 million Americans have nearsightedness, with about 10 million of those having severe nearsightedness. 14.2 million Americans have farsightedness and 1 in 3 people have astigmatism (see below).
Astigmatism is the lesser known refractive eye error because fewer people have this. Your eye should be naturally shaped like a sphere, equally bending the light from all angles. Under normal circumstances, light will enter your eye, where it bends and forms into an image at the back of your eye (on the retina). However, in a person with astigmatism, light will bend in one direction more than another, or focuses at two different points, which causes blurry vision. Typically, an astigmatic eye has curves that are steeper in one direction than the other.
Astigmatism is caused when your eye is not completely round—it is more of a rugby ball shape. That shape will throw off how light is bending and is the cause of different directions of light. It is possible that light focuses at more than two points in patients with astigmatism. Common symptoms of this specific eye error include headaches, blurred or distorted vision, squinting to see, eyestrain, discomfort or the patient has night vision problems. This condition can easily be corrected with glasses or contact lenses.
Some patients will have astigmatism present at birth and the cause is genetics or a simple mutation when the eye was growing. Studies show that this condition isn’t worsened with reading in poor light, the television or other activities. There is an eye condition called keratoconus, which is when the cornea becomes thinner and cone-shaped over time. Patients who have this may start to develop astigmatism because of the changing eye shape.
Astigmatism has two types: regular and irregular. The irregular version can be caused by corneal scars or scattering that happens in your eye lens. You must have special prescription contacts to make your vision clear. Regular—or more common—astigmatism will be a result of the shape of your cornea or lens that scatters light irregularly. Custom lenses like toric lenses can be issues to correct your blurry vision. If you prefer eyeglasses instead of contacts, you may need special cylindrical lenses to counteract the directions your eye is bending light.
Because you only have two eyes for your entire lifetime, you want to do all that you can to protect your vision so it stays healthy. There are countless people who have perfect vision until the day they die. However, they likely take care of their vision through proper eyewear, eye exams and a nutritious diet. If you want all of your eye tissues to work properly, make sure you’re getting adequate vitamins and minerals each day. A lack of these will impair cell repair and the vision process. That means wearing UV sunglasses anytime you are outside and wearing computer (blue-light blocking) glasses whenever you use electronic and digital devices.
Refractive eye errors simply happen to most people no matter what they do. There are activities that can make those eye errors worsen, such as reading in low light or sitting right in front of a television. However, genetics plays a major role in whether you will have blurry vision or not. The best way to detect blurry vision (especially a slight blur) is to have a comprehensive eye exam. We can test your eyes for refractive eye errors like nearsightedness, farsightedness and astigmatism, plus any abnormal changes to the eyes. If you have astigmatism, you will need a slightly different type of prescription that you can’t get over-the-counter. To schedule your vision exam today, call Peeper’s Optical at (303) 223-040!