Figure 1 – A simulation of how nearsightedness is perceived
Nearsightedness, also called myopia, is a condition of the eyes that results in blurred vision when viewing a distant image. If a patient is nearsighted, they will see well up close (sometimes very close to theirs eyes) but they can’t clearly see objects that are far away. The image to the right (Figure 1) shows an island scene with distance clarity (left) and blurred vision caused by myopia (right). Myopia is very common, and is easily treated with glasses, contact lenses, or refractive surgery (such as LASIK or PRK). Myopic patients tend to have more retinal problems due to the shape of their eyes making regular eye care for nearsighted patients an essential part of their health care.
Figure 2 – This patient sees nice and clear without any vision correction.
A normally-functioning eye is not too long or too short (which would make it farsighted), but is just right (see Figure 2). When light rays enter this normally-seeing eye, they focus perfectly on the back of the eye at the retina and the patient’s perception is a clear image. This patient would theoretically need no glasses for viewing distant objects because their eye is the appropriate length to maintain a nice, clear image for distance-viewed objects.
Figure 3 – This is a nearsighted eye that is not wearing vision correction and has not had LASIK or PRK.
When an eye is nearsighted, it typically is nearsighted because the eye is too long, from the front to the back (see Figure 3). This eye would result in a patient that cannot see clearly at distance without their glasses or contact lenses. The image in this eye is focused in front of the retina and the patient sees a blurry image. A nearsighted eye can be corrected by our optometrists with glasses, contact lenses, or refractive surgery so that they see clearly at distance. An eye that was nearsighted because it is too long can now appreciate a nicely focused image because something is compensating for the power of the eye.
Figure 4 – This is a nearsighted eye that sees great because the patient is wearing contacts/glasses or has had LASIK/PRK.
Figure 4 shows an eye that is still long front to back, though a clear image results because this diagram is representative of a nearsighted eye that is wearing a contact lens, glasses, or has had LASIK or PRK to correct their distance vision. Notice that even in the eye that has had LASIK, the eye itself is still elongated front to back even though it still sees very clearly (Figure 4). This eye is still nearsighted, even though the patient’s glasses prescription may or may not be myopic, because only the power at the front of the eye (the cornea) has been changed. The length of the eye remains the same.
A nearsighted eye as compared to an eye that is not nearsighted, tends to be longer and thus the retina at the back of the eye can be considered under tensional stress from the elongation. Myopic eyes tend to have more retinal holes, tears, and detachments, thus necessitating regular eye care. Nearsighted eyes are certainly not guaranteed to have retinal problems, though the odds are higher as compared to a non-nearsighted eye. It is for this reason that myopic patients should definitely get their eyes checked by our eye doctors, and our doctors frequently dilate the pupils of these patients so that they can check the retinas to be sure there is no preventative treatment that is required. Prevention is a key theme to our eye exams!
Please call Vista Eye Care today to schedule your annual comprehensive eye and vision examination! (303) 450-2020