A menu gets harder to read. Your phone starts drifting toward arm’s length. If that sounds familiar, you may be noticing presbyopia: the age-related loss of your eye’s ability to focus up close.1
The basic idea is this: bifocal contact lenses put near and distance focusing powers into the same lens. Some present light from both powers to your eye at once; others move slightly so you look through a different part. Here’s what happens in each case.2
Your eye needs a little help up close.
Inside your eye, a natural lens changes shape to help focus light on the retina, the light-sensitive tissue at the back. As that lens becomes less flexible with age, nearby detail gets harder to bring into focus. Contact lenses add optical help in front of the eye; they don’t make the natural lens young again.1
Read the animation
- A flexible natural lens changes shape to focus a nearby object on the retina.
- Presbyopia reduces that flexibility, leaving light from the near object out of sharp focus on the retina.
- A contact lens supplies added near power in front of the eye.
- This helps focus near light without restoring the natural lens’s flexibility.
Two powers work at the same time.
Many soft bifocal and multifocal contacts use simultaneous vision. Different powers contribute light to the retina at the same time. For the object you’re looking at, some of that light is better focused than the rest. Your visual system learns to make use of the clearer information.2
The example below uses alternating rings of near and distance power. Both remain present when you change your gaze from the scenery to a book. You don’t need to find a little reading window.
Read the animation
- One lens contains near and distance powers in concentric rings.
- The pupil admits light through more than one power at once.
- For a distant object, the distance contribution is better focused while the near contribution adds defocused light.
- For a near object, the near contribution is better focused while both powers still contribute.
- The brain interprets the combined visual information without either power switching off.
A small shift changes the view.
Segmented, or translating, bifocals work differently. Typically made as rigid gas permeable lenses, they have a distance zone above a near zone. Looking straight ahead positions the distance zone over the pupil. As you look down to read, the lower eyelid supports the lens, which shifts upward relative to the eye. That brings the near segment in front of the pupil.3
Read the animation
- The upper portion of this lens provides distance power and the lower portion provides near power.
- In straight-ahead gaze, the pupil looks through the distance zone.
- On downward gaze, the lower eyelid supports the lens while the eye moves down behind it.
- The lens has moved upward relative to the eye, bringing the near zone in front of the pupil.
- Looking straight ahead restores the distance alignment.
Bifocal or multifocal: what’s the difference?
Bifocal means two main focusing powers, usually near and distance. Multifocal is the broader term for more than one power; many designs also support intermediate tasks, such as looking at a computer screen. You’ll often see the terms grouped together when shopping, but the lens design and your fitted prescription matter more than the category name.6
What does wearing them feel like?
The aim is fewer interruptions to reach for reading glasses. There can be a trade-off: some wearers notice softer contrast, glare, or hazy vision, particularly in low light. Getting the right balance between near and distance vision can take adjustment and follow-up visits. Reading glasses may still help with demanding tasks.4 6
Your eye care professional will consider your prescription, pupil size, lens fit, and everyday vision needs. Tell them what matters most—small print, screen work, or driving after dark—so the trial reflects your real life.3
Learn more
Do bifocal contacts work like bifocal glasses?
Translating contacts use a similar upper-distance, lower-near arrangement. Simultaneous designs work differently: several powers contribute light at once, without requiring you to look through a lower reading segment.2
Are they the same as monovision?
No. In conventional monovision, one eye is corrected mainly for distance and the other mainly for near. Bifocal or multifocal contacts put more than one power in an individual lens.4
Can they help if I have astigmatism?
Sometimes. Toric multifocal contacts combine astigmatism correction with multiple focusing powers. Whether a particular lens is suitable depends on your prescription and fitting.5
References
These references informed the original illustrations, which are simplified and not to scale.
- National Eye Institute. “Presbyopia.”
- American Academy of Ophthalmology EyeWiki. “Contact Lenses,” presbyopia section.
- Bausch + Lomb. Correction of Presbyopia with GP Contact Lenses, especially pp. 20–21 and 59–60.
- CooperVision. “Multifocal Contact Lenses.”
- ACUVUE. “Multifocal Contact Lenses.”
- Remón et al. “Bifocal and Multifocal Contact Lenses for Presbyopia and Myopia Control.” Journal of Ophthalmology (2020).
