What is Farsightedness or Hyperopia?
Farsightedness is exactly what the words are far sighted. Other names are hypermetropia or longsighted. Hyperopia is the medical term and farsighted is the common term. Many people believe that if you are farsighted, you can see clearly at distance without wearing a eyeglass correction. That belief is not correct. If someone is only slightly farsighted, they can have fairly good vision at distance without glasses. The correct medical term for seeing clearly at distance and not needing corrective lenses is called emmetropia.
Whether someone is nearsighted or farsighted is determined by the size and shape of the eye. Hyperopia is the result of the shape of the cornea being too flat and the size of the eye is too small. This leads to a person having trouble seeing clearly up close and if farsighted enough to have blurred vision at distance as well. As an object is moved closer, the power of the cornea and the size of the eye make it so that the lens of the eye is unable to bring the object into focus.
Refractive errors occur when the shape of the cornea and the size of the eye will not focus light onto the surface of the retina clearly Hyperopia is one type of refractive error. Myopia or nearsightedness and astigmatism are other types of refractive errors.
Symptoms of Hyperopia or Farsightedness
- Blurred vision at distance
- Blurred vision at near
- Asthenopia or eye strain
- Strabismus or crossed eyes can be associated with farsightedness
- Headaches after reading for periods of time
- Headaches or eye strain with watching TV or looking at a computer for a period of time
Diagnosis of Farsightedness
Farsightedness and other refractive errors are diagnosed during an eye examination. A refraction is performed where you look through a machine that has many lenses inside and tell the eye doctor or his staff which lenses you can see clearly through at the chart on the wall. This machine is called a phoropter. There are other machines that can help provide the eye doctor with determining a refractive error:
- Wave front analyzer
- Tracey Technology System
- Treatment of Farsightedness
- The common methods of treatment are eyeglasses and contact lenses.
Eyeglasses for the Farsighted
The lens that corrects hyperopia is called a convex lens. The lens is thicker in the middle and thinner on the edge. It bends light quicker to focused point on the retina and shaped likea magnifying glass.
Contacts for Hyperopia
Contacts can correct hyperopia by bending light in the same manner as eyeglasses. There are soft contact lenses and rigid gas permeable contacts.
Surgical Correction of Hyperopia
LASIK or Laser-Assisted in situ Keratomileusis
LASIK surgery is an operation where the eye surgeon creates a flap of tissue on the anterio surface of the cornea. The Excimer laser removes tissue in a manner that makes the shpe of the cornea steeper which corrects the hyperopia. This should only be performed after the eye surgeon has determined that the hyperopia is not progressing.
PRK or Photorefractive Keratectomy
The eye surgeon removes the outer epithelium of the cornea and does not make a flap. The Excimer laser removes the corneal tissue to change the shape of the cornea. A bandage contact lens is usually placed on the cornea after the procedure.
LASEK or Laser-Assisted Subepithelial Keratectomy
A flap of only epithelium is made on the surface of the cornea. The Excimer laser then performs the procedure. A bandage contact lens is usually placed on the cornea after the procedure.
CK or Conductive Keratoplasty
A radio frequency probe is applied to the cornea. The collagen is heated by the probe shrinking the collagen in the cornea. This causes the shape of the cornea to steepen, correcting the farsightedness. The results of the CK in many cases reverse over time.
Farsightedness or hyperopia is most commonly treated by wearing eyeglasses or contact lenses. Surgical correction before age 60 should be done with caution as the eye progressively becomes more farsighted in our forties and fifties.