What are the refractive errors and how are they corrected?

I’m sure you’ve heard about the most common types of refractive errors: myopia, hyperopia or farsightedness, astigmatism and presbyopia . If you are not familiar with the topic of eye defects or have just entered the “club” of people who have to wear glasses or contact lenses, be sure to read this column.  

Having glasses does not mean that all people who wear them suffer from the same condition or the same problem in their visual health. It is not the same for a child to wear glasses to be worn by a person over 60 years of age. There are different types of refractive errors or eye functioning, so to speak, which alter the 20/20 ideal vision.



In general, the human eye functions like a camera. The light enters and its rays are refracted (deviated) as it passes through the cornea and lens. The lens of the lens forms an inverted image of the objects that focuses on the retina and the retina acts as a light sensitive film, sending electrical impulses to the brain through the optic nerve. The latter interprets these electrical impulses and converts them into the images we see.

In a healthy eye, light is focused directly on the retina without problems. However, with the passage of time, or due to hereditary factors, so-called refractive errors may occur.

Refractive errors occur when the shape of the eye prevents light from being focused directly on the retina. This can occur due to variations in the length of the eyeball, changes in the shape of the cornea or deterioration in the lens. These errors can occur in both children and adults, although some are more common as age increases or if there is a family history.

Below you will find the most common refractive errors:

  • Myopia : occurs when the light is focused in front of the retina and not on the retina. As a result, distant objects are blurred and nearby objects are clearly visible. It is also called near vision.
  • Hyperopia or Hyperopia : occurs when light is focused behind the retina instead of directly on it. As a result, nearby objects are blurred and far away, with greater clarity. It is also called far vision.
  • Astigmatism : occurs when the light is not focused evenly on the retina, which prevents the clear focus of objects. As a result, it looks blurry or elongated.
  • Presbyopia or presbyopia : happens over the years and refers to the difficulty to focus on nearby objects.

Many people do not know they have vision problems . However, at other times, the symptoms do not take long and it is necessary to visit the ophthalmologist to make an accurate diagnosis. You should consult the eye specialist if you notice:

  • Blurry vision
  • Double vision
  • Headaches
  • Visual fatigue

You should also consult him if you squint to see or see halos around bright lights.

Problems or refractive errors can be corrected once the cause is determined. An examination that often includes dilatation of the pupil, among other studies, is usually required. The treatment includes eyeglasses or glasses, contact lenses or surgery. Your doctor will guide you according to your case so that you have a 20/20 vision again.

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