What additional power do Multifocal lenses provide for presbyopia correction?

Multifocal lenses are specifically designed to address the vision needs of individuals with presbyopia, a condition that typically occurs with age and impairs the ability to focus on close objects. These lenses provide additional power in the form of 'ADD power', which is the term used to describe the extra magnifying power incorporated into multifocal lenses for near vision tasks.

The term 'ADD' signifies the additional strength (usually a positive power) combined with the distance prescription in the lens to facilitate clear vision at various distances, particularly for near work, such as reading or using a smartphone. Thus, when a person looks through the lower portion of multifocal lenses, they benefit from this added power that helps to focus on objects that are close up.

This approach allows individuals with presbyopia to seamlessly transition their focus between distant and near objects without the need for switching between different pairs of glasses, which hugely enhances convenience and visual efficiency.