Farsightedness – Causes, Symptoms, Diagnosis, Treatment

Farsightedness (hyperopia) is a common vision condition in which you can see objects in the distance clearly, but objects nearby may be blurry.

The degree of your farsightedness determines your focusing ability. People with severe farsightedness see clearly only objects a great distance away, while those with mild farsightedness may see clearly objects that are closer.

Farsightedness usually is present at birth and tends to run in families. A basic eye exam can confirm farsightedness. You can easily correct this condition with eyeglasses or contact lenses. Another treatment option is surgery.

Causes

Your eye has two parts that focus images:

  • The cornea, the clear front surface of your eye
  • The lens, a clear structure inside your eye that changes shape to help focus objects

In a perfectly shaped eye, each of these focusing elements has a perfectly smooth curvature like the surface of a rubber ball. A cornea and lens with such curvature bend (refract) all incoming light in such a way as to make a sharply focused image directly on the retina, at the back of your eye.

A refractive error
However, if your cornea or lens isn’t evenly and smoothly curved, light rays aren’t refracted properly, and you have a refractive error. Farsightedness is one type of refractive error. It occurs when your cornea is curved too little or your eye is shorter than normal. Instead of being focused precisely on your retina, light is focused behind your retina, resulting in a blurry appearance for close-up objects. However, if you haven’t reached the age when the eye becomes presbyopic (gradually loses the ability to focus actively on nearby objects) — usually around middle age — you may be able to exert enough focus so that nearby objects are seen clearly.

Other refractive errors
In addition to farsightedness, other refractive errors include:

  • Nearsightedness (myopia). This occurs when your cornea is curved too much or your eye is longer than normal. The effect is the opposite of farsightedness. Light is focused in front of your retina, making faraway objects blurry. You’re able to see nearby objects clearly.
  • Astigmatism. This occurs when your cornea or lens is curved more steeply in one direction than in another. Uncorrected astigmatism blurs your vision. Typically, the blurred vision occurs more in one direction than in another — horizontally, vertically or diagonally.

Symptoms

Farsightedness may mean:

  • Nearby objects may appear blurry.
  • You need to squint to see clearly.
  • You have eyestrain, including burning eyes, aching in or around the eyes, and, rarely, a headache.
  • You experience general eye discomfort or a headache after a prolonged interval of doing close tasks, such as reading, writing or drawing.

Diagnosis

Farsightedness is diagnosed by a basic eye exam. Three kinds of eye specialists, each with different training and experience, can provide routine eye care:

  • Ophthalmologist. An ophthalmologist is an eye specialist with an M.D. (doctor of medicine) degree. He or she is trained to have a thorough understanding of all serious eye conditions and the treatment options available to you. Ophthalmologists perform eye surgery when it’s necessary.
  • Optometrist. An optometrist has an O.D. (doctor of optometry) degree. For the most part, an optometrist is limited to evaluating vision, prescribing corrective lenses and diagnosing common eye disorders. Complex disorders including those that require surgery are managed by ophthalmologists.
  • Optician. An optician is an eye specialist who fills prescriptions for eyeglasses — assembling, fitting and selling them. Some states also allow opticians to sell and fit contact lenses.

A complete eye examination involves a series of tests. Your eye doctor may use odd-looking instruments, aim bright lights directly at your eyes and request that you look through an array of lenses. Each test allows your doctor to examine a different aspect of your vision.

According to American Academy of Ophthalmology, recommendations for regular eye exams include:

Adults
If you don’t wear glasses or contacts, have no symptoms of eye trouble and are at a low risk of developing eye disease, it’s recommended that you have an eye exam at the following intervals:

  • At least once between ages 20 and 39
  • Every two to four years between ages 40 and 64
  • Every one to two years beginning at age 65

However, if you wear glasses or contacts, have your eyes checked every year. And if you notice any problems with your vision, schedule an appointment with your eye doctor as soon as possible, even if you’ve recently had an eye exam. Blurred vision, for example, may suggest you need a prescription change.

Additionally, if you’re at high risk of certain eye diseases, such as glaucoma, have your eyes checked every three to five years between the ages of 20 and 29.

Children and adolescents
Children need to be screened for eye disease and have their vision tested by a pediatrician, an ophthalmologist or another trained screener at the following ages and intervals:

  • Between birth and 3 months
  • Between 6 months and 1 year
  • Around 3 years
  • Around 5 years

Your child or adolescent may need more frequent visits if he or she experiences any problems with vision or has symptoms of eye trouble. In addition, children and adolescents who have a disease that puts their eyes at risk, such as diabetes, may need more frequent eye exams.

Treatment

The goal of treating farsightedness is to help to focus light on the retina through the use of corrective lenses or refractive surgery.

Corrective lenses
For most young people, the lenses of their eyes are flexible enough to compensate for the condition due to their ability to focus on nearby objects. Therefore, most young people with farsightedness don’t need corrective lenses. But by middle age, the lenses become less flexible and most farsighted people need corrective lenses to improve their near vision.

Wearing corrective lenses treats farsightedness by counteracting the decreased curvature of your cornea or the smaller size (length) of your eye. Types of corrective lenses include:

  • Eyeglasses. The variety of eyeglasses is wide and includes bifocals, trifocals and reading lenses.
  • Contact lenses. An alternative to eyeglasses is contact lenses. A wide variety of contact lenses are available — hard, soft, extended wear, disposable, rigid gas-permeable (RGP) and bifocal. Ask your eye doctor about the pros and cons of contact lenses and what might be best for you.

    Monovision contact lenses are commonly used by farsighted people who have started to experience presbyopia. With monovision contacts, you may not need correction for the eye you use for distance vision (usually the dominant eye), but a contact lens can be used for close-up vision in your other eye. Some people have trouble adapting to this kind of vision because 3-D vision is sacrificed in order to have the advantage of seeing clearly both nearby and in the distance. Monovision contacts can be worn intermittently as desired.

    Modified monovision contact lenses are another option. With this type of contact lenses, you can wear a bifocal contact lens in your nondominant eye and a contact lens prescribed for distance in your dominant eye. You can then use both eyes for distance and one eye for seeing objects nearby.

Refractive surgery
Although most refractive surgical procedures are used to treat nearsightedness, they can also be used for farsightedness. These surgical treatments correct farsightedness by reshaping the curvature of your cornea. Refractive surgery methods include:

  • Laser-assisted in-situ keratomileusis (LASIK). LASIK is a procedure in which an ophthalmologist uses an instrument called a keratome to make a thin, circular hinged cut into your cornea. (In some centers, the use of a keratome has been replaced by the use of a specially designed laser.) Your eye surgeon then uses an excimer laser to remove layers from the center of your cornea to steepen its domed shape. An excimer laser differs from other lasers in that it doesn’t produce heat. After the excimer laser is used, the thin corneal flap is repositioned.
  • Laser-assisted subepithelial keratectomy (LASEK). Instead of creating a flap in the cornea, the surgeon creates a flap involving only the cornea’s thin protective cover (epithelium). Your surgeon will use an excimer laser to reshape the cornea’s outer layers and steepen its curvature and then reposition the epithelial flap. To facilitate healing, a bandage contact lens often is worn for several days after the procedure.
  • Photorefractive keratectomy (PRK). This procedure is similar to LASEK, except the surgeon removes the epithelium. It will grow back naturally, conforming to your cornea’s new shape. PRK may be more uncomfortable than LASEK. Like the LASEK procedure, PRK requires the use of a bandage contact lens for a few days following surgery.
  • Conductive keratoplasty (CK). This procedure uses radiofrequency energy to apply heat to tiny spots around the cornea. The effect resembles plastic wrap being stretched by heat. The degree of change in the curvature of the cornea depends on the number and spacing of the spots as well as the way in which the cornea heals after treatment. The results of CK are variable.