According to the World Health Organization, Refractive Error is one of the most common eye disorders. In a basic sense, Refractive Error occurs when the eye cannot focus images from the outside world.
The four most common refractive errors are:
- myopia (nearsightedness): difficulty in seeing distant objects clearly;
- hyperopia (farsightedness): difficulty in seeing close objects clearly;
- astigmatism: distorted vision resulting from an irregularly curved cornea, the clear covering of the eyeball.
- presbyopia: which leads to difficulty in reading or seeing at arm’s length, it is linked to ageing and occurs almost universally.
Learn more from the World Health Organization.