Yes. A diffractive trifocal intraocular lens (IOL) introduces a small but measurable reduction in contrast sensitivity compared with a high-quality aspheric monofocal lens implanted in the same eye¹. This is not a manufacturing defect; it is a direct optical consequence of how the lens works. Splitting incoming light across three focal points means that at any given focal distance, only a fraction of the available light is contributing to the image. The remainder is forming the other two foci.
In published comparative studies, the reduction in contrast sensitivity is most evident under mesopic conditions (low-light viewing, such as dusk or night driving), particularly at higher spatial frequencies, and is the optical substrate behind patient reports of dimmer-looking images at night and a perception of haloes around point sources of light². In photopic conditions (well-lit daytime viewing), with a healthy retina and a clean ocular surface, the difference is typically subclinical and the patient does not notice it.
What This Means in a Glaucomatous Eye
This is the central reason trifocal implantation is approached cautiously in glaucoma. A glaucomatous optic nerve has fewer functioning ganglion cells available to transmit the image, and the contrast tax the lens imposes lands on an already-narrowed channel. In healthy retinas the cost is paid out of reserve; in glaucomatous retinas there is less reserve to pay it from.
The clinical implication is not to refuse trifocal lenses in every glaucoma patient. It is to be honest with the patient about what the lens does, to verify that their disease band and ocular surface can tolerate it, and to document the conversation. The patients who do best with trifocal optics are those who understood, before surgery, that they were trading a small amount of image quality for spectacle independence.
References
- Mojzis P, Peña-García P, Liehneova I, Ziak P, Alió JL. Outcomes of a new diffractive trifocal intraocular lens. J Cataract Refract Surg. 2014;40(1):60-69.
- Cochener B, Boutillier G, Lamard M, Auberger-Zagnoli C. A comparative evaluation of a new generation of diffractive trifocal and extended depth of focus intraocular lenses. J Refract Surg. 2018;34(8):507-514.
Related Topics
- Why Trifocal Lenses Are the Lens of Choice for the Glaucoma Patient Wanting Spectacle Independence
- Why Ocular Surface Disease Matters Before Premium Lens Surgery
- What Is a Goal-Lens Mismatch in Cataract Surgery?
- Can Glaucoma Patients Have Trifocal Lenses?
- Is Mild Glaucoma a Contraindication to Trifocal IOLs?
- What Level of Glaucoma Is Suitable for Premium IOLs?
- Do Trifocal IOLs Reduce Contrast Sensitivity?
- Do EDOF Lenses Give True Spectacle Independence?
- Is an EDOF Lens the Right Choice for a Glaucoma Patient?
- Can You Monitor Glaucoma After a Trifocal IOL?
- When Is a Monofocal IOL the Right Lens for a Glaucoma Patient?
