Nearsightedness or myopia is a very common condition in which the light coming into the eye is not focused properly onto the retina, making it difficult to see objects far away. The condition is usually caused by an elongation of the eyeball. If you are nearsighted, you typically will have difficulty seeing distant objects clearly, but will be able to see well for close-up tasks such as reading and using your cell or computer. Farsightedness or hyperopia is the opposite and is usually caused by a shortening of the eyeball that may occur over time. People who are farsighted can see distant objects very well, but have difficulty focusing on objects up close. Farsightedness is a common vision problem, which, affects about a fourth of the population. Nearsightedness is also very common, affecting about a third of the population. Let’s bring the causes, symptoms and treatments for these two conditions into focus.
MYOPIA
Nearsightedness or myopia is where the eyeball is longer than it should be, which means that when you are looking at an object far away, the image comes into focus in front of your retina and appears blurry. If you move closer to the object, that point of focus within your eye moves farther back until it focuses on the retina, and you see clearly, hence the ‘near’ in nearsightedness. The more nearsighted you are the closer you must hold something to see or read it clearly. Myopia is very common, and is usually diagnosed between the ages of 8 and 12. Your eyes are growing at this age, so the shape of your eyes can change. Adults usually remain nearsighted if they have the condition as a child.
Other reasons for the development of nearsightedness include certain health problems such as diabetes, and visual stress, such as concentrating too hard on written materials for long periods of time or spending too much time in front of a computer screen. Nearsightedness can also be an inherited condition. If one or both of your parents are nearsighted, you have a high chance of developing the condition as well.
HYPEROPIA
Farsightedness or hyperopia occurs when your eye is too short in relation to the curvature of your cornea. Light rays entering your eye focus behind the retina, basically overshooting your focusing capability, producing instead a blurred image. Essentially, farsightedness causes light to focus behind your retina instead of directly on it. You may be born with farsightedness or develop it over time. Farsightedness often develops in adults as the lenses of the eyes age. This normal change in the eye’s focusing ability is called presbyopia. Beginning in the early to mid-forties, the lens in your eye becomes more rigid and most adults may start to experience problems with their ability to clearly see objects up-close, such as newspapers, books, menus, cell phones, and computer screens.
SYMPTOMS
The most obvious symptom of nearsightedness is blurred vision when looking at objects faraway. Adults might not be able to see street signs clearly while driving and children may have difficulty seeing the blackboard at school. Other signs of nearsightedness include tired eyes, squinting, and headaches.
If you’re farsighted, your eyes have to work harder to see anything up close. This causes eyestrain, and can also cause blurred vision up close, tension, fatigue, and squinting as you try to adjust your focus. Farsightedness in children can contribute to problems with their academic performance, such as learning to read and write.
TREATMENT
Your eye-care expert can diagnose nearsightedness and other refractive errors during a comprehensive dilated eye examination. The common method of measuring vision loss is the Snellen Test Chart, the familiar rows of increasingly smaller letters. The more myopic you are, the more blurred distant objects appear, the higher your prescription needs to be. You may need to wear corrective eyeglasses or contact lenses all the time or just for certain activities, such as driving or watching television. Refractive or laser eye surgery is a permanent form of correction for nearsightedness. This surgery reshapes your cornea to focus light onto the retina.
Some farsighted people can use their focusing muscles to pull the image forward onto the retina, allowing them to see clearly. The simplest way to correct farsightedness is to get prescription eyeglasses or contact lenses. These corrective lenses change the way light enters your eyes, helping you focus better.
Both myopia and hyperopia are easily corrected through the use of corrective glasses or contact lenses. Be safe and proactive and schedule a comprehensive eye examination with your eye-care expert at least once a year. Having regular eye exams helps catch problems before they get worse; this is doubly important if you have a health condition that could affect your vision, such as diabetes or high blood pressure. Call your eye-care expert immediately if you notice any sudden changes in your vision or have suffered an injury to your eyes. At iSight Optometry we help you see the world more clearly, bringing what’s important to you into focus. Contact us today to learn more.