What Is an Intraocular Lens (IOL)?
In cataract surgery, after the clouded crystalline lens is removed, an artificial lens (an intraocular lens, or IOL) is implanted in its place. The lens you choose has a major impact on how you see after surgery and how much you will depend on glasses — making lens selection a key part of cataract surgery.
Types of Intraocular Lenses
- Monofocal IOL (covered by insurance): The standard lens, focused at a single distance — either far or near. After surgery, glasses are used for other distances.
- Toric IOL (covered by insurance): A lens that corrects significant corneal astigmatism. Astigmatism-correcting versions are available for both monofocal and multifocal lenses.
- Multifocal IOL (selective treatment): Provides focus at multiple distances — far and near — greatly reducing dependence on glasses.
- Trifocal IOL (selective treatment): A type of multifocal IOL that distributes focus across three points: far, intermediate, and near.
- Extended depth-of-focus IOL (EDOF) (selective treatment): A new-generation lens that prioritizes natural vision and reduces nighttime glare.
What Is "Selective Treatment"?
Cataract surgery with a multifocal IOL falls under Japan's "selective treatment" (sentei ryoyo) system. The surgery itself — examinations, the surgical procedure, and medications — is covered by national health insurance, and you pay only the price difference between the multifocal lens and a monofocal lens. This lets you choose a multifocal IOL at a lower cost than fully self-paid private treatment.
How to Think About Lens Selection
- A lifestyle centered on reading, computer work, or smartphones → a multifocal IOL is a strong option
- A job involving frequent nighttime driving → consider a monofocal IOL with glasses, or an extended depth-of-focus lens
- A lifestyle centered on sports and the outdoors → a multifocal IOL is also worth considering
There is no single "right answer" in lens selection. During your consultation, we take time to ask about your work, hobbies, and how often you drive, and we combine this with the condition of your eyes (degree of astigmatism, the state of your retina and cornea) to recommend the lens that fits you best.
Approximate Costs (Self-Paid Portion)
With a multifocal IOL under the selective treatment system, an out-of-pocket lens fee is added to the usual insurance-covered cost of surgery. Depending on the type of lens, this is approx. ¥300,000–¥400,000 per eye (JPY), varying by facility and lens. Please confirm exact costs with each medical institution.
Monofocal and toric IOLs are covered by national health insurance, with no additional lens fee.
Points to Consider
Points to consider: With multifocal IOLs, some people experience "halos" — rings of light around lights at night — or "glare," an uncomfortable sensitivity to bright light. Contrast sensitivity may also be slightly reduced, so we take care to explain these effects in advance and to ask about your lifestyle in detail. In some eyes, a multifocal IOL may not be suitable, in which case we will explain why and may recommend a monofocal IOL instead.
About Cataract Surgery
For details on the surgery itself — the procedure, how long it takes, and possible complications — please see our cataract surgery page.