Someone with farsight has hyperopia

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Hyperopia Introduction

Hyperopia, is one of the two most frequently experienced of eye problems. The casual name for Hyperopia is farsightedness. The disorder is caused by refractive errors of the eye which means that the eye cannot focus correctly.

Refractive disorders of the eye

When the eye fails to refract light properly for focusing on the fovea of the retina it is commonly called a refractive disorder. Refracting means the bending of light. However in medical eye care terms it refers to the thickness of the eye lens.

Refraction takes place when light travels through a medium of greater density. Normally light travels in a straight line however when it hits a flat surface, such as the cornea lens, it travels at right angles.

When light travels into the cornea, the difference in density between the outside air and the cornea of your eye causes the light to refract and focus onto the retina with the help of the eye lens. The eye then needs to accommodate in order to refract light form various distances, objects and angles. The lens of the eye accordingly adjusts its power for focusing adaptability.

The eye lens

The refractive power of an eye lens is calculated in dioptres (D).

There are mainly two groups of lenses:

  • A 'plus' lens is convex and focuses light inwards to the retina
  • A 'minus' lens is concave and sheds light outwards away from the retina

The higher the calculation of the dioptre of a lens, the stronger is its power in either plus or minus count.

Hyperopia or Near Sightedness

Hyperopia also known as hypermetropia or farsightedness happens when the eyeball is too small to bend light rays properly. This causes the eyes to be unable to focus properly on objects that are near. The result is blurry vision. It can also cause problems with focusing on objects at a distance. The eye needs to increase its power in order to produce an image on the retina.

Clinical signs of hyperopia

Hyperopia is characterized by blurred visions, asthenopia, problems focusing on words, strabismus, and amblyopia.

Correction of hyperopia

For people with hyperopia the standard treatment is the prescription of ‘plus’ lenses, but surgery is also an option. LASIK surgery, a form of non-invasive laser surgery, is the most popular and effective operation for the correction of mild and moderate hyperopia. For severe cases, intraocular lens implantation is the recommended surgical treatment.

Hyperopia can have many degrees and forms so there is no absolute guideline as to how to fix it. Mild farsightedness may not be treated in children as research has shown that a child might grow out of it. However if there is too much strain on the eyes the child is at risk of becoming cross-eyed.

Hyperopia when left untreated also increases a person’s risk of developing glaucoma.