What is myopia?
Myopia, also known as short sightedness and near sightedness, is an eye condition which is reaching epidemic proportions worldwide. It causes blurry distance vision, while objects up close remain clear and in focus. This most often happens because the eyeball grows longer than normal.
The definition of myopia is having a refractive error (or glasses prescription) of at least -0.50D in one or both eyes.
The opposite of myopia is hyperopia or hypermetropia (also known as long sightedness), which means having a refractive error of +0.50D or more. Hyperopia can cause blurry reading or close vision, and higher levels of hyperopia can also cause blurry distance vision.
Optometrists distinguish between myopia and hyperopia during an eye examination. Believe it or not, sometimes one condition may mimic the other and several specialised tests may be required. Simply reading letters on a chart at a GP’s office or at a school vision screening does not give any information or diagnosis about what someone’s eye condition is.
The definition of high myopia has varied over the years, however it is generally considered to be high when the spectacle prescription reaches -5.00D or greater in one or both eyes. The higher the amount of myopia, the higher the risk of eye diseases such as glaucoma, cataract, macular disease and retinal detachment. You can read more on our dedicated ‘Myopia and Eye Disease’ page.