Shortsightedness is also known as myopia and occurs because the eyeball is too long, so that the image at the back of the eye is focused in front of the retina rather than onto it.

Symptoms include distance blurring. A person with shortsightedness sees clearly at short distances, but cannot see clearly at longer distances. Shortsighted people will find objects come clearer as they move closer to them.

Shortsightedness can occur at any age but often begins during the teenage years, or in the early twenties. When it occurs at a very young age, visual development is not usually hindered as the child can do close tasks happily and much of their interest is in objects nearby. It is often not until school blackboards need to be read that blurred distance vision becomes a problem. Once a driving licence is sought significant shortsightedness must be corrected.

Shortsightedness is corrected with a diverging lens that will move the image back onto the retina, making distant objects clear once again. The correction of shortsightedness usually includes the use of spectacles (or sometimes contact lenses) which may be worn all the time or only for certain tasks at distance. Both clarity and comfort are improved which results in better visual efficiency.