Hyperopia ( Farsightedness )
Hyperopia – also known as longsightedness – is the ability to see things clearly from a distance, but not up close. It is the opposite of myopia (near sighted), which is another refractive vision disorder, along with astigmatism (distorted vision).
How Hyperopia Works
Farsightedness is a hereditary condition, present throughout childhood. Most people with hyperopia usually do not notice symptoms of farsightedness until early adulthood, when the eye muscles can no longer control it. The inability to see close objects is due to a mismatch between the eyeball’s length front-to-back, and the cornea’s refractive power.
The eye’s length is fixed, providing a set distance between the cornea and the retina. Incoming light should be refracted by the cornea and lens so as to focus clearly on the retina. But the cornea in a hyperopic eye is too flat given the fixed eyeball length.
- Light coming from far objects needs less refraction to focus on the retina
- Light coming from near objects needs more refraction to focus on the retina
A hyperopic eye, with its relatively flat cornea, has less refractive power than a normal eye or myopic eye. It gives fine clear vision for distant objects but cannot refract light enough when it comes from near objects. So the light carrying those near images cannot focus on the retina, but focuses behind it, and you have blurry near vision.
Correction for Farsightedness
- As with myopic people, there are three main options for those with hyperopia:
- Refractive Surgery
By adding a third lens into the mix, in addition to the cornea and lens, glasses correct the refractive error according to how severe it is for the individual. The same is true of contact lenses.
Refractive surgery would be LASIK (or one of its variants such as IntraLase), or PhotoRefractive Keratectomy (PRK). These two procedures both use an excimer laser to reshape the corneal layer called the stroma. Since the stroma is the second layer down, beneath the epithelium on the surface, access to it must be somehow achieved.
It is in creating this access that the two procedures differ:
- LASIK creates a surface flap, bends it back on a hinge, and then replaces it after the work is done
- PRK entirely removes a thin layer of surface tissue and you would wear a bandage contact lens for about two weeks while those cells grow back.
For some, LASIK is the better choice, and for others, PRK is better. That is something that you can discuss with your eye surgeon. To find an experienced and qualified ophthalmologist in your area, you can use the map on this page, or the form on this page.