Types of Refractive Errors

Refractive errors occur when light is prevented from focusing directly on the retina. You may find it difficult to see objects at a certain distance due to blurry vision. In severe cases, refractive error can causes visual impairment. Let’s discuss on the 4 different types of refractive errors and how to manage them. 

Myopia

Myopia or most of us refer as short sightedness, is a common vision impairment where distant objects may appear blurry, while near objects are clear. Short sightedness occur when the eyeball is longer than normal, resulting the light to shift its focus to the front of the retina instead of on the retina itself. Therefore when light travels into the eyes, the light is not focused properly, thus projecting distant objects blurry. Otherwise, short sightedness occurs when the cornea is too curved.

Myopia can be discovered from the early days of a child, therefore an eye exam is essential for detecting early signs to avoid affecting their performance in school. Beside genetics, excessive eye strain especially long hours of exposure on the computer screen or reading, can also be a risk factor for Myopia. This condition can be easily corrected with eyeglasses or contact lens.

Hyperopia

Hyperopia, also known as far sightedness is a less common refractive error as compared to Myopia. This condition allows a person to see objects clearly when they are distant but blur if they are near. Being opposite to short sightedness, the eyeball is shorter than normal which cause the light to fall behind of the retina. Thus, nearer objects would be seen as blurry.

In some cases, children who are born farsighted could lessen their hyperopia as their eyeball lengthens in their natural aging process. Although Hyperopia is not preventable, it has to be treated to avoid problems such as headaches, eye strain, discomfort and burning sensation on the eyes. Wearing eyeglasses or contact lens would be the easiest way to correct Hyperopia.

Astigmatism

Astigmatism is commonly associated with other refractive error like Myopia and Hyperopia. They are all similar in terms of effecting the light as it travels into the eye. Astigmatism happens when the clear front surface of your eye is irregularly shaped or mismatched curves on the inside of your eye. Due to the irregular shape, the light is prevented from focusing on the retina, which results vision to be blurry.

Astigmatism can be caused by many factors, such as biological inheritance, eye surgery or injury. However, astigmatism can increase or decrease in time as the curve of lens on the inside of your eye changes.

Presbyopia

Presbyopia is a condition that happens as you get older. The aging of the eye causes it to lose its original flexibility to adjust its shape to focus on near objects. As a result, people with Presbyopia would experience difficulty in seeing fine objects or small prints on books and newspaper, unless the reading item is placed at a certain distance.

This condition can be treated by wearing bi-focal eyeglasses or contact lenses. Although this vision condition may be similar to Hyperopia, Presbyopia would usually affect people after their 40’s. While, Hyperopia often occurs from a young age.

We hope that this clarifies the 4 different types of refractive errors of the eye. If you experience blurry vision, it is best to visit an eye doctor at your earliest time to receive proper treatment.