Distance, Intermediate or Near

The vast majority of implants used today are "monofocal" implants.  That simply means the implants are "single focus" implants.  Just like the magnifying lens that as a child one used to focus the light to burn a leaf, the monofocal implants in the eye bring the complete focus onto the central processing center of the eye called the "macula."

So one can focus on the lens for distance.  This is how the vast majority of patients choose and is truly the default mode for most surgeons.  With ideal results, the patient will be able to focus on the far away objects.  Driving can be accomplished easily, watching TV, watching baseball game at the stadium, watching the waterfall, scenery....

The focus at the intermediate is bit more tricky.  It is neither perfect for distance, nor for complete near, but it has some elements of both.  The intermediate is considered the range of 20 inches or 50 cm (2.0 D) to 40 inches or 100 cm (1.0D).  Many people are most comfortable at 1.5D or 66cm or 26 inches.  This focal point allows most people to function fine without glasses for most everyday household functions, reading the cell phone, working on your desktop computer and reading the cookbook.  But if you want to drive at nights plan on corrective glasses for the full distance.  If you are planning on sitting down and reading for while or doing your taxes, plan on reading glasses.

Near focus is a difficult choice.  I have several patient that tell me that the biggest pleasure in their life is to curl up with a book at night and fall asleep with it.  The intermediate vision is not sufficient for this task.  One would need a 2.5D focus or 16 inches (40 cm) to 3.0D focus or 13 inches (33 cm).  This would allow for a perfect, comfortable near read of a book, iPad, Nook or a similar item.  However the distance vision is now quite compromised and requires full corrective glasses most of the time.

Can you have it all?

The answer is really, YES.  With the advent of the "Multifocal" implants.  The implants are designed to deliver multiple focal points that allow the patient to have clear vision at all of the distances, far, intermediate, and near!