Eye health: Long-sightedness
In its simplest sense, far-sightedness, long-sightedness or hyperopia means that the eye focuses better on distant objects than on those that are close.
Children with mild to moderate degrees of long-sightedness can see both near and far without correction because the muscles and lens within their eyes can overcome the long-sightedness. Adults with hyperopia or long-sightedness may have difficulty focusing on objects close up, such as print in a book. As they mature, these same adults may have difficulty focusing on distant objects, as well.
What causes long-sightedness?
Hyperopia is a refractive error, like astigmatism and short-sightedness (myopia). Having a refractive error means that light rays bend incorrectly into your eye to transmit images to the brain. Ideally, the cornea and lens, the two focusing structures in the eye, focus images directly on the surface of the retina. If the eye is too short, or the focusing power too weak, the image is focused behind the retina. At the retinal surface, the image is blurred. Thus, the vision, too, is blurred.
Hyperopia often runs in families. It is often present at birth; however, many children outgrow it.
What are the symptoms of long-sightedness?
Symptoms of long-sightedness may include:
- Eye strain.
- Difficulty concentrating or focusing on nearby objects.
- Fatigue or headache after performing a close task such as reading.
If you experience these symptoms of hyperopia while wearing your glasses or contact lenses, you may need a new prescription.
How is long-sightedness diagnosed?
Long-sightedness can be easily diagnosed by a basic eye examination given by your optician.
How is long-sightedness corrected?
To correct hyperopia you must change the way the light rays bend when entering your eye. Glasses, contact lenses, or refractive surgery can all be used to correct long-sightedness.
Depending on the extent of your long-sightedness, you may need to wear your glasses or contact lenses at all times, or only when you need to see objects up close, like when reading or sewing. With hyperopia, your prescription is a positive number, such as +3.00. The higher the number, the stronger your lenses will be.
If wearing contacts or glasses isn't for you, refractive surgery can reduce or even eliminate your dependence on glasses or contact lenses. The most common procedures to correct hyperopia include:
- PRK. During a photorefractive keratectomy, a laser is used to shape the cornea so that light rays can focus closer to, or even on the retina.
- LASIK. During laser-assisted in situ keratomileusis, a flap is cut through the top of the cornea, a laser removes some corneal tissue, and then the flap is dropped back into place. LASIK is the most common surgery used to correct long-sightedness.
Talk to your optician or eye specialist about which treatment is best for you.