Trifocal vs EDOF Lenses: What Are the Differences?

Trifocal intraocular lenses aim to create three focal points for distance, intermediate and near vision, while EDOF lenses aim to extend the range of clear vision. Reducing the need for reading glasses is more prominent with trifocal lenses; EDOF lenses prioritise distance and intermediate vision. Glasses may still be needed for small print with either type.

This difference does not mean that one lens is better for everyone. It is considered together with nighttime driving, computer viewing distance, reading habits, and the overall health of the eyes. It cannot be said that all EDOF lenses will provide the same visual quality or the same light effects, given that there are different optical designs under the name EDOF.

Trifocal lens, a three-focal lens used in cataract surgery or when replacing a natural eye lens in a suitable patient. It aims to increase the possibility of performing daily activities without glasses at various distances. It differs from contact lenses that are fitted and removed into the eye.

Dividing light between different focal points may cause halos, glare or changes in low-light visual quality in some people. These optical effects should be discussed alongside the benefit for near vision. More information is available in trifocal lenses guide provides this information.

EDOF means extended depth of focus. The aim is to provide a broader range of clear vision beyond a single distance focus. Distance tasks and intermediate activities such as computer use may be prioritised; glasses may still be needed for small print or very close work.

The optical mechanisms of EDOF lenses are not the same. Designs can be found that incorporate diffractive, non-diffractive, or combine different technologies. Therefore, statements such as “EDOF never creates a light ring” or “makes all distances appear without glasses” are not accurate. EDOF lenses page explains the assessment process.

Both lens groups can aim to provide distance vision. The result depends on more than the lens name: accurate biometry, any residual prescription after surgery, astigmatism and the health of other eye tissues also matter. The optical design of a lens cannot eliminate disease of the retina or optic nerve.

Intermediate vision is assessed for daily activities such as computer use and working at a kitchen counter. Trifocal lenses provide a separate focus for this distance, while EDOF lenses aim to support it with an extended range of clarity. For near vision, trifocal lenses are often considered with greater expectations of reading without glasses; actual performance depends on the model and the individual.

If close work and small print are priorities, the near focus of a trifocal lens may offer an advantage. Sensitivity to light effects and expectations for night vision must also be considered. Someone choosing EDOF may accept reading glasses for small print. Neither option guarantees complete independence from glasses.

A halo is a ring seen around a light source. Glare and dazzle are other optical symptoms that may be noticed after surgery. Dividing light into different focal points with trifocal lenses may cause these effects. Some EDOF designs aim to reduce them but do not eliminate them completely.

A person engaging in nighttime driving should clearly state this before surgery. The extent to which light effects are tolerated varies from person to person. Post-operative complaints should not only be considered as “adaptation,” but rather, the eye surface, remaining refractive error, and other potential causes should be evaluated.

It is possible to evaluate toric options for both lens groups in appropriate eyes. The toric feature is directed towards reducing astigmatism; trifocal or EDOF features, on the other hand, define the refractive zone. These are not interchangeable terms.

Corneal measurements, whether astigmatism is regular and the planned lens axis are assessed. Previous laser surgery is important information for lens calculations. Trifocal toric and EDOF toric options are explained in separate guides.

Visual acuity, glasses prescription, corneal structure, the ocular surface and biometry are examined. The retina, macula and optic nerve are assessed, with additional imaging when needed. Problems such as dry eye that affect measurements may need to be treated first.

Macular disease, significant optic nerve damage or an irregular cornea may make some lenses less suitable. Alternatives such as monofocal lenses may then be discussed. Selection is not based solely on age, lens price or the term “smart lens”.

The most frequently used visual distances throughout the day, as well as expectations regarding work, nighttime driving, and the need for glasses, should be shared. For example, someone who works constantly on a computer and someone who does close-up handiwork may have different priorities. The coordination of both eyes is also considered.

During lens evaluation in Samsun, existing eyeglasses, previous surgical information, and any prior eye measurements may be brought. The benefits, limitations, and potential need for additional eyeglasses should be discussed together in order to make a decision.