During the concepts of the cataract article I already mentioned the need of an intraocular lens. In this article, I’ll explain a bit more regarding these lenses.
There are over 500 available models world-wide. Each surgeon is offered around a hundred different models. Each model with its own particular optical behaviour and signature from each firm. We group them by the amount of optical focus they have (don’t worry, you’ll understand it later on).
This lens is a classic. It grants the best visual acuity for distant objects. But patients will need reading glasses and also for intermediate vision (such as computers). Already within this group, we could make some subdivisions depending on the current eye condition. All in all this is the go-to in case of doubts, wanting to save money or in difficult cases.
Pros: cheap, the insurance usually pays for the cost, top visual quality, every single eye accepts these lenses.
Cons: intermediate and reading glasses are needed.
Bifocal lenses already grant us another focusing point. These lenses allow us to get rid of the glasses when it comes to reading. However, intermediate vision is not perfect, so bifocal lenses may be a suitable option for patients who don’t use a computer on a regular basis (for example)
Pros: no need of reading glasses, excellent visual quality.
Cons: intermediate price, insurance doesn’t usually pay for the cost, not the best visual quality, intermediate visual acuity is limited, rings on the vision at night.
Here we have the latest of the latest. This lens has 3 focusing points: far, intermediate and reading. Offering the patient the possibility to forget about glasses forever in every single distance. In exchange, visual quality is not the best. Although patients are usually extremely pleased with the results, this lens is not recommended for some jobs (i.e. photographers, painters…). This intraocular lenses are quite restrictive when it comes to the conditions for success; so patients with previous history of squint eye, amblyopia, eye trauma… are advised against this sort of lenses.
Pros: no more glasses, for ever.
Cons: expensive, not covered by insurance, good visual quality, circles at night, may need of glasses for reading in dark rooms.
More over, both trifocal and bifocal lenses have rings engraved on the surface. These rings create some weird phenomenon: circles around the lights at night. The brain gets used to it within the first weeks and patients stop seeing them on the short-term.
On top of that, we have to take astigmatism into account. Patients who have astigmatism, specially over a 1 diopter, are recommended to choose a specific lens to fix it. All previous lenses (monofocal, bifocal and trifocal) have its own astigmatism-fixing option, called toric lenses.
So in the end the questions are:
-How much do you want to get rid of the glasses? If you don’t want to get rid of them or are not really that troubled by them, get the monofocal lens.
-Do you use the computer regularly? If not, go for the bifocal.
-If you want to forget about the glasses and use the computer, you should consider the trifocal lenses. However, you should be aware of the circles and do a thorough examination to discard any contraindications.
Actually, when it comes to our daily practice, people over the eight decade tend to choose the monofocal. Younger patients (50s-70s), who want to get rid of both the cataract and the glasses, tend to go for the trifocal lens. This is a major trend, but the patient always gets the last word.
Consider getting an appointment if you want further information on intraocular lenses.