Myopia
What is myopia?
Myopia, or nearsightedness or shortsightedness, is a vision condition in which near objects are generally seen clearly, but distant objects are blurred and do not come into focus. Myopia is a term that comes from a Greek word meaning "closed eyes." Myopia is not a disease, nor does it mean that you have "bad eyes." It simply refers to a variation in the shape of your eyeball. The degree of variation determines whether or not you will need corrective eyewear.
What are the symptoms of myopia?
Generally patients with myopia have trouble seeing in the distance.
What causes myopia?
Good vision occurs when light is focused directly onto the retina. Myopia most commonly occurs because the eyeball is either too long (from front to back) or too powerful to focus an image onto the retina. The image is focused in front of the retina, as pictured above. When the image is not directed onto the retina, it is interpreted to us as a "blur."
Who develops myopia?
It is thought that the eyeball shape variation is due to both genetic factors (running in families) and environmental factors, including increased amounts of nearwork and device-use.
Nearsightedness is a very common vision condition that affects nearly 30 percent of the American population.
How is myopia diagnosed?
Myopia is often suspected when a parent teacher notices a child squinting to see a blackboard or an object in the distance. Sometimes children will be seen sitting closer to television sets to see more clearly. A child may also perform poorly during a routine eye screening. Further examination by our optometrists will reveal the degree of the problem.
A comprehensive eye examination by our optometrists will confirm the diagnosis of myopia. When problems are suspected, it is important that the child has a comprehensive eye health examination to determine the nature of the problem and to rule out serious eye diseases. When vision conditions are treated properly, the child will enjoy the best possible sight.
How is myopia treated?
Corrective concave (minus power) lenses in the form of glasses or contact lenses are prescribed to help focus light more precisely on the retina, where a clear image will be formed. Depending on the degree of myopia, glasses or contact lenses may be needed all of the time for clear vision. If the degree of impairment is slight, corrective lenses may be needed only for activities that require distance vision, such as driving, watching TV, or in sports requiring fine vision.
Refractive surgery, or LASIK, is also a viable option in many instances. This procedure reshapes the cornea by removing a small amount of eye tissue using a highly focused laser beam to help you see more clearly.
Orthokeratology is also a great option for many patients. Also known as corneal refractive therapy, or CRT, this is a non-surgical procedure that involves wearing specially designed rigid contact lenses to reshape the curvature of your cornea. The lenses are worn overnight, and allow for clear vision during the day without the need of glasses or contact lenses.
Our optometrists will explain these options in more detail to help you decide which of these procedures is right for you.
What is the prognosis for myopia?
Myopia usually occurs between the ages of 8 to 12 years. Since the eyes continue to grow during childhood, nearsightedness almost always occurs before the age of 20. Often the degree of myopia increases as the body grows rapidly, then levels off in adulthood. Although with the recent increased use of near-devices, we are finding that this age where myopia levels off is coming at later and later ages.
During the years of rapid growth, frequent changes in prescription eyewear may be needed to maintain clear vision. It is important to bear in mind that the frequent changes in prescription are not making the eyes "weaker". During the growth period that occurs during the teen years, the eye is also growing rapidly and hence the degree of blur is also increasing. As the growth cycle slows, the prescription changes slow correspondingly. Should the progression not slow down, there are many methods for myopia control that the optometrist can discuss with you.
Yearly examinations should follow after myopia has been discovered to determine whether the condition is changing and whether a change in prescriptive eyewear is needed. Eye exams also help to ensure that vision impairments do not interfere with daily activities.