Refraction is the scientific term for the bending of light as it travels through one object to another. Vision happens when light rays are bent or refracted as they travel via the cornea and the lens. Light is trained on the retina, which converts the light-rays into signals that are sent to the brain via the optic nerve. The brain then translates these signals into the images we see.
A refractive error - also known as a refraction error - is one of the most common eye disorders. It means that the eye's shape does not bend light correctly so that it cannot focus on the right area of the retina. This results in blurred or unfocused images.
What are the causes of
The main cause of a refractive error is an irregularly shaped cornea, where the eyeball's length may be too short or too long. As people age, the ability to focus up close also becomes difficult because of the greater rigidity of the ageing lens. Overuse of the eyes, however, is not believed to be a cause of refractive error.
What are the types of refractive error?
There are many different types of refractive error, all of which can vary among individuals as to the degree of severity. Here are the most common:
Light focusses in front of the retina rather than on it. This means that far away objects are blurred and indistinct but nearby objects are clearly visible. Untreated myopia can cause headaches as a result of eyestrain, and squinting - the need to partially close the eyelid to try and see.
This is a condition where light fails to focus on a single point on the retina, resulting in blurred or stretched-out vision. Double vision, headaches and squints are common symptoms of astigmatism.
This is a form of refractive error where light focuses behind the retina rather than on it. People with hyperopia can see objects at a distance but have problems focussing on things that are close up. This is a condition that is likely to worsen with age.
This is an age-related refractive error where the lens is no longer flexible enough to change shape and allow the eye to focus clearly on near objects.
Refractive Error F.A.Q's
How can you prevent refractive error?
Recent research suggests that a lack of sunlight in early childhood and the teen years can increase the risk of myopia so ensuring children spend plenty of time outside seems a sensible precaution. In the past, some people believed that it was possible to correct refractive errors by performing regular eye exercises, but there is no evidence to suggest there is any benefit to doing this. Unfortunately, there is no scientifically proven way of preventing a refractive error; it is either a genetic or an age-related condition. The good news is that visual impairments caused by a refractive error can usually be completely corrected.
It cannot be emphasised enough how important it is to have your eyes tested regularly. For more information about refractive errors and any other eye problems and conditions, please contact the Orbit Eye Hospital in Mumbai, which provides an extensive range of high-quality ocular treatments.