Presbyopia is the gradual loss of the eye’s ability to focus on nearby objects, caused by the ageing of the eye’s lens. The lens in your eye becomes less elastic with age and is therefore less able to change shape. This process is called accommodation: the lens becomes more rounded to see clearly up close and flatter for distance vision. With presbyopia, this adjustment becomes increasingly difficult.
Most people first notice presbyopia around the age of 40, for example because they have to hold the newspaper further away or struggle to read small text on their mobile phone. It is a natural part of ageing and affects everyone, regardless of whether you already had a different prescription or have always had perfect vision.
Presbyopia is neither a disease nor an eye condition, but a refractive error resulting from the normal ageing of the eye. It differs from long-sightedness (hypermetropia), although both can cause problems with near vision. In long-sightedness, the eyeball is too short or the refractive power is too low; in presbyopia, the lens has become too stiff.