|A farsighted eye is too “short,” causing light to converge behind the retina and blurring near vision.
Farsightedness, medically known as hyperopia (hi-pur-OH-pea-uh), refers to vision that is good at a distance but may be poor at close range. Farsightedness occurs when the eyeball is shorter than normal, as measured from front to back, or when the cornea has too little curvature. This reduces the distance between the
cornea and retina, causing light to converge behind the retina, rather than on it.
Since we’re usually born with eyes that are too short, the majority of newborns are farsighted. As we grow, the “normal” eye gets longer and by 1 year, close vision is generally clear. Even when it doesn’t, farsightedness – also known as hypermetropia and long-sightedness – may go unnoticed until middle age – when the
ciliary muscles controlling the
lens begin to weaken and can no longer compensate for the limitation in near vision. This is why farsightedness, which is usually congenital, often isn’t apparent until the development of
Disease such as
retinopathy, eye tumors and lens dislocation can also contribute to farsightedness, which is easily treated with corrective lenses and can also be managed with refractive laser surgery.
People who are farsighted typically have good distance vision, but may find it difficult to do close visual tasks, such as reading. Besides blurred vision or difficulty focusing during close activities such as reading or sewing, other symptoms include:
Aching, burning, red or tearing eyes
Headaches or “brow” aches (occurring on the top of the eye), which can result from overworked ciliary muscles
Poor hand-eye coordination
Severely farsighted children may appear cross-eyed – a condition called accommodative esotropia that usually develops around age 3 and may be constant or intermittent.
Farsightedness is largely believed to be inherited, with little evidence that enviromental factors cause its development. However, to avoid accentuating symptoms, your eyecare practitioner may recommend that you keep work areas well-lit and glare-free and give your eyes a break during close visual work by focusing on distant objects every 30 minutes or so.
Occasionally, conditions such as diabetes, lens dislocations and eye tumors can cause farsightedness. So if you experience any symptoms, see your eye doctor for a complete examination. Children should get a complete eye exam by age 3 and those with severe hyperopia need to be monitored to avoid the development of
crossed eyes (strabismus) or
lazy eye (amblyopia).
If you are mildly farsighted, your eyecare practitioner may not recommend corrective treatment at all, since your ciliary muscles may be compensating by adjusting the shape of your lens to bring close vision into focus. However, if you are moderately or severely hyperopic or presbyopic, you have several treatment options:
- Corrective Lenses
- Eyeglasses with convex lenses, which are thicker in the center and thinner on the edges, to bend light to converge further forward in the eye to reach the retina.
- Contact lenses offer several options, such as soft lenses and rigid gas-permeable (RGP) lenses, which conform to the shape of the lens.
Laser surgery is effective for many people with farsightedness, but the long-term effects of these relatively new procedures are still being studied. Laser surgery, which still may result in the need for reading glasses, is generally not recommended for those under age 18 and carries risk of side effects such as increased sensitivity to glare, seeing halos around lights, poor vision, dry eye and others. Options include:
- LASIK (laser in situ keratomileusis) is a procedure in which a surgeon slices a flap into the cornea and a laser removes some tissue from beneath the sliced area to reshape the cornea.
- Photorefractive keratotomy (PRK) uses a laser beam to remove tissue from the outer surface of the cornea, reshaping it to improve its focus.