3 Common Refractive Errors Explained

31 March 2015
 Categories: , Blog

Refractive errors impact on your eyesight over time and are diagnosed when you have a routine eye examination. If you have a refractive error, light cannot reach the retina in the back of your eyes at the optimum angle for perfect vision. Instead, an abnormality in a part of your eye that helps you focus on images, such as the cornea or lens, causes light to enter your eye from a different angle than it should. This can cause blurred vision, eye strain, increased sensitivity to light, and headaches.

You may have symptoms indicating a refractive error or your vision may seem fine to you until you get the results of your eye test. Refractive errors are corrected with prescription glasses and contact lenses can sometimes be used depending on the nature and severity of the error. Here's an overview of three common refractive errors:


Myopia, also known as short-sightedness, causes your eyes to focus anything you're looking at directly in front of your retina. Myopia causes distant objects to appear blurry and out of focus. Objects within arm's length can be seen with no problem, so you'll have to wear glasses when looking at distant objects such as when visiting the cinema or when driving.


Hyperopia, also known as long-sightedness, causes your eyes to focus behind the retina. This makes it difficult to clearly see or focus on items that are within arm's length, but distant objects can be seen with no problems. When trying to focus on close objects such as a computer screen, you may experience headaches or eye strain.

Mild hyperopia is common in toddlers, but it can resolve on its own before they start school. However, if your child stands or sits very close to the television when watching their favourite program, consider booking an eye examination to determine the extent of their long-sightedness.


Astigmatism is defined as having an uneven curve in your cornea, which is the clear covering over your eyeball. This means light rays aren't focused on a single point in your retina. Instead, light enters your eye and lands on several parts of your retina, which causes visual distortion.

Astigmatism can be present alongside long-sightedness or short-sightedness. It can be corrected by attaching a small piece of glass, known as a prism, to the lenses of your prescription glasses, which your optician can do for you. This corrects the angle that light enters your eyes, which means your eyes don't have to strain to focus on objects.

Correcting refractive errors can prevent your eyesight from deteriorating further. If you don't have any symptoms of refractive errors, it may be you're only mildly affected at the moment or your eyes have deteriorated so slowly you've not noticed a dramatic change in your vision. Regular eye tests can spot early signs of deterioration in your sight, so schedule an appointment with a business such as Bay Optical if you're overdue.