REFRACTIVE ERRORS
Refractive Errors
If you have a refractive error, it means that the shape of your eye does not bend (or refract) light the proper amount. This can cause you to have blurred or distorted vision, or to have difficulty reading or seeing well up close. There are four main types of refractive error:
- Myopia (near sightedness): near objects are clear, and distant objects are blurred. This is often inherited, and typically discovered in childhood when vision is noted to be poor in school or at a pediatrician’s office. This usually progresses while a child is growing, and stabilizes in the late teens. Occasionally, myopia may occur (or worsen) in older individuals as a result of progressing cataract formation.
- Hyperopia (farsightedness): close objects are more blurred than distant objects. This usually progresses with age. When hyperopia is mild, distant objects are clear but near vision is blurred. As hyperopia progresses, vision is often blurry at both near and distance.
- Astigmatism: objects can be blurred or distorted at all distances. This most commonly occurs when the front surface of the eye (the cornea) is asymmetrical rather than being equally curved in all directions. Astigmatism can be present at any age, and often progresses gradually with age.
- Presbyopia (aging eyes): focusing at near becomes more difficult, making it difficult to read up close. This progresses with age through the 40’s and 50’s, as the lens inside the eye becomes more rigid and can no longer change its shape to focus at near. This is a normal part of the aging process, occurs in just about everybody, and can be associated with myopia, hyperopia, or astigmatism.
Overuse of the eyes does not cause (or worsen) these types of refractive error. Refractive errors are diagnosed, or confirmed, during and eye examination at our office. This is done while you are looking at an eye chart made up of letters (or other images). A set of lenses is used, often in conjunction with optical or computerized equipment, to make your vision as clear as possible.
Refractive errors are most commonly treated with corrective lenses such as spectacles (eye glasses) or contact lenses. In some cases, refractive errors can be corrected or improved by certain types of surgery, such as LASIK or Cataract surgery.
If your vision seems to be worsening, or if other people can see things clearly that you cannot, schedule an appointment for an eye examination to see if refractive error is the cause.
