The most common vision problems are refractive errors, more commonly known as:

  1. nearsightedness (myopia)
  2. farsightedness (hyperopia)
  3. astigmatism
  4. presbyopia


Refractive errors occur when the shape of the eye prevents light from focusing directly on the retina. The length of the eyeball (either longer or shorter), changes in the shape of the cornea, or aging of the lens can cause refractive errors. Most people have one or more of these conditions.


Myopia (nearsightedness) is a most common vision condition , where near objects can be seen clearly than distance objects and can be corrected easily using prescription glasses especially designed to counter act the effect. A concave lens (minus powered) is placed in front of a myopic eye, bending the light to refract properly on retina to clarifying the vision.


Hyperopia (farsightedness) is less common vision condition where distant objects may be seen more clearly than near objects, hyperopic person may experience symptoms differently some people may not notice any problems with their vision especially when they are young. It can be corrected by a convex lens (plus powered) by placing it in front of a hyperopic eye, diverging light to focus properly.


Astigmatism is common and usually minor vision condition that caused blurred or distorted vision, it occurs when the cornea or crystalline lens isn’t perfectly curved shape, many people who wear glasses have some degree of astigmatism. It can be corrected by a compound convex or concave lens by placing it in front of a astigmatic eye, lining up light on both meridians.


Presbyopia is a natural part of aging process and caused by changes to the lens inside the eye ball. As people age, the lens became harder and less elastic making it more difficult for the eye to focus on close objects. It is a type of refractive error along with myopia, hyperopia and astigmatism. It can be corrected using single vision, bifocal and progressive lens.

Who is at risk for refractive errors?

Presbyopia affects most adults over age 35. Other refractive errors can affect both children and adults. Individuals that have parents with certain refractive errors may be more likely to get one or more refractive errors.

What are the signs and symptoms of refractive errors?

Blurred vision is the most common symptom of refractive errors. Other symptoms may include:

  • Double vision
  • Haziness
  • Glare or halos around bright lights
  • Squinting
  • Headaches
  • Eye strain

How are refractive errors diagnosed?

An eye care professional can diagnose refractive errors during a comprehensive dilated eye examination. People with a refractive error often visit their eye care professional with complaints of visual discomfort or blurred vision. However, some people don’t know they aren’t seeing as clearly as they could.

How are refractive errors corrected?

Refractive errors can be corrected with eyeglasses, contact lenses, or surgery.