The trifocal lens: freedom from glasses at all distances

Among the types of intraocular lenses, the trifocal lens is the one that offers the most freedom from glasses. Unlike the monofocal (a single focus) and the EDOF (a continuous range from far to intermediate), the trifocal focuses three defined distances: far, intermediate and near. It is the lens designed for those who want to do without glasses for reading too. In this article I explain how it achieves this, what visual quality it offers, what trade-offs it has —night halos and glare— and, above all, who is not a good candidate.

How a trifocal lens works

Put simply, the lens splits the incoming light into three simultaneous images, each focused at one distance: far, intermediate and near. The brain learns to keep the sharp image at any given moment and to ignore the other two.

In more technical terms: most trifocals use a diffractive design, with microscopic concentric rings that diffract the light and create those three foci. It is the same principle that explains both its advantages (seeing at all distances) and its drawbacks (part of the light is split, and that has an optical cost).

What visual quality it offers

The trifocal provides very good functional vision at all three distances and is the lens with which most patients manage to live without glasses. That said, by splitting the light into three foci, contrast is slightly lower than with a monofocal, and it is the design most associated with night-time light phenomena. The most modern models have greatly improved this balance, but the trade-off, to a greater or lesser degree, is always there.

That is why I always insist on the same point: the trifocal is not “the best lens”, but an excellent tool for the right patient. The key is in the selection.

Glare and night halos

This is the point that must be discussed with complete honesty. The diffractive design can produce halos (rings of light around bright points) and glare or starbursts, especially at night and while driving. It is not a sign that anything has gone wrong: it is part of how the lens works.

The good news is that these phenomena usually fade over time. The brain adapts —what we call neuroadaptation— and the severity of halos and glare decreases noticeably between the first and the sixth month after surgery. I explain it in detail in the article on night halos and intraocular lenses.

Reference: meta-analysis on visual disturbances with trifocal lenses and the role of neuroadaptation (PMC, 2025).

Who is not a good candidate for a trifocal

This is perhaps the most important part of the whole article. A trifocal in the wrong eye can give a poor result even if the surgery is perfect. There are two large groups of patients in whom, as a rule, I do not recommend it.

For anatomical or ocular health reasons

When the eye does not meet the necessary optical conditions, the trifocal is not advisable:

Amblyopia (lazy eye) or strabismus, where baseline visual quality is already compromised.
Irregular corneas (keratoconus, previous refractive surgery with high aberrations), which degrade the image the lens creates.
Macular or retinal disease, advanced glaucoma or severe dry eye, which reduce quality and tolerate the light-splitting of a diffractive lens poorly.

For lifestyle or visual demands

Even if the eye is perfect, there are profiles for whom the trade-offs of the trifocal are not worth it:

Night or professional drivers, for whom halos and glare can be a real nuisance at work.
Photographers and professionals who depend on maximum image quality and contrast.
Very perfectionist or demanding people —often myopes used to very sharp near vision— who tolerate any small optical compromise poorly.

In these cases, an EDOF, a monofocal plus or a monofocal are usually more sensible options. Detecting this before surgery, with a proper assessment and an honest conversation about expectations, is what prevents disappointment.

In summary

The trifocal lens is the one that gives the most freedom from glasses: seeing far, at the computer and reading without depending on them. In exchange, it asks you to accept slightly lower contrast and some night-time phenomena that usually fade with neuroadaptation. It is a magnificent lens for the well-selected patient, and a poor choice for those who are not. That is why, as always, the decision is made after an individualised assessment.