What are multifocal contact lenses?

Definition

Multifocal contact lenses incorporate different powers within a single lens to allow focusing at several distances. They are also called progressive contact lenses and are mainly intended for people with presbyopia.

Instead of correcting only distance or only near vision, they distribute the powers so that the eye and brain can use the appropriate zone for the task: reading, looking at a screen or driving.

Relationship with presbyopia or tired eyes

Presbyopia is the gradual loss of the ability to focus up close that appears naturally with age, usually from around 40-45. It is not a disease, but a physiological change in the lens of the eye.

Multifocal contact lenses are one of the options for compensating for this near-focus difficulty while maintaining good distance vision.

Single-vision versus multifocal

A single-vision lens has a single power and corrects one distance only. If you use it to see well in the distance, you will probably need reading glasses for close work.

A multifocal lens, by contrast, combines several powers to cover several distances with the same lens, reducing the need for additional glasses in many everyday situations.

Multifocal contact lenses versus progressive glasses

Although they share the goal of correcting several distances, they work very differently. With progressive glasses, you move your gaze across the lens (up for distance, down for near). With a multifocal contact lens, the different powers are distributed in another way and the brain selects the useful image through simultaneous vision.

As a result, the visual experience is not identical and fitting takes time: it is not simply a matter of swapping one solution for another.

The optical principle in simple terms

Simultaneous vision means that more than one image reaches the retina at the same time. With practice, the brain learns to prioritise the sharp image and ignore the blurred one depending on what you need to see.

• Distance vision: for driving, watching television or getting around outdoors.
• Intermediate vision: key for the computer, the car dashboard or cooking.
• Near vision: for reading, using your phone or detailed close work.

The role of the brain and realistic expectations

Adapting to multifocal contact lenses is both optical and neurological. The visual system needs a learning period to interpret the simultaneous images correctly.

Realistic expectations are essential. Visual quality can be very good, but it does not always exactly match that of glasses perfectly prescribed for a single distance.