Most people are aware of bifocal glasses, or even progressive
lenses (no-line bifocals). These types of glasses allow us to see
distant and nearby objects in clear focus by looking through
different parts of the lenses. When cataract surgery is done, a
lens implant replaces the crystalline lens of the eye. It is now
possible to use a multifocal lens implant. This differs from
bifocal glasses because you will always look through the same part
of the lens, regardless of what distance the object you are
looking at is away from you. Instead, distant and nearby objects
will be in focus simultaneously.
The ReSTOR lens has concentric rings to enable focusing on near
and far objects. This gives you clear vision for reading, driving,
golfing, watching TV, looking at your cell phone, shaving,
applying make-up, etc. The intermediate range of vision
(approximately an arm’s length away) is not as sharply focused as
objects in the normal reading distance or beyond a couple of
metres. For those who require the intermediate range in sharp
focus, a mild pair of glasses may still be required.
Early designs of the multifocal lens produced very visible rings
around lights, especially when driving at night. While these rings
are still present, they are very thin and much less noticeable.
Most people learn to ignore the rings after a short period of
time.
As with any lens, it is important to understand that there is more
to vision than how light focuses inside the eye. Individuals with
other eye problems, such as macular degeneration, may be advised
against multifocal lens implants. |
