Great Near, Intermediate and Distance Vision After Cataracts
A cataract used to mean eventual blindness. These days it means a short eye surgery to give you a new lens.


/Vision-Eye Care News Articles/ - SACRAMENTO, CA, December 15, 2006 - Before talking about cataracts, let's look at how our eyes are set up, so we have a context.
How our eyes work
Our eyes are spheres, whether they look round in our faces or not.
· The cornea is the clear curved part at the front, part of the tough outermost layer called the sclera
· The iris is the adjustable colored part around the black center pupil, which is an opening that lets light into the inside of the eyeball
· The iris has muscles that make it smaller, thereby making the pupil larger, allowing in more light; and that make it larger, making the pupil smaller and admitting less light.
· The retina is the back inside surface of the eyeball, which senses the light
· It contains a chemical ('visual purple') which converts the light into electrical impulses, which are carried by the optic nerve to the brain. The place where this nerve (and some blood vessels) exit the retina is the optic disk, and is a blind spot. Luckily, each of our eyes covers for the blind spot in the other, so we aren't aware of having these two blind spots.
The lens
The lens is a clear disk, convex on both sides, that's attached top and bottom by muscles to the eyeball. On the front side of it is the vitreous humor, a gel-like substance, and on the back side is the aqueous humor, more watery, as the name suggests.
So when light enters our eyes on its way to the retina, it passes through:
· The cornea
· The vitreous humor
· The lens, and
· The aqueous humor
That light is coming from something we're looking at, let's say our house. From its source (sun, moon, flashlight, streetlight), the light arrives at our house, and is reflected off those surfaces all around. That part of it reflected towards us can enter our eyeballs and arrive on our retina, forming an image there of our house.
Accommodation
The lens is adaptable in shape, depending on how far away our house is as we look at it. The muscle attached to the lens (the ciliary muscle) can pull it to be more convex, or more concave, so that we can focus at different distances, and this is known as accommodation. As we age, typically our lenses become more stiff, so that they don't respond fully to the muscle movement. That's when we notice that we need reading glasses, or perhaps bi-focals.
What are cataracts?
If there's anything amiss with the cornea, humors or lens, our house will look a bit off. A cataract is a cloudy area that gradually grows in the lens. It impedes the light flow through to the retina, causing our house to have a blurry garage, for instance, or blurry roof.
Cataracts are changes in the cells making up the lens. Their cellular protein becomes hazy and eventually white, yellow or brown, blocking vision.
Causes of cataracts
We don't completely know what causes cataracts. Some things that appear to contribute are:
· Diabetes
· Glaucoma
· Detached retina
· Injury to the lens
· Prolonged use of some drugs
· Too much exposure to X-rays
The visual difficulty works in reverse too. An eye doctor looking at your eyes can't see through the cataract and may miss some other developing problem, like damage to the optic nerve.
Cataract symptoms
Since they develop slowly, the vision loss creeps up on us, but at some point we start noticing:
· Objects looking dull or blurred, maybe just on one side
· Poorer vision at night
· Halos around lights at night
· Less ability to focus on near objects
· Glare on sunny days or in any bright light, because the cloudiness in the lens scatters light rather than focusing it
· Whites, purples and blues becoming more gray
Treatment
An eye surgeon can insert an intraocular lens (IOL) to replace the natural, now defective lens. This is known as Clear Lens Extraction and Replacement (CLEAR) Surgery.
CrystalensÔ
This is a replacement lens which mimics the way our natural lens flexes and focuses.
It has what they call "hinges" which allow it to bend in response to muscle movement. There's a re-learning process after it's been inserted, where you learn how to focus it. Most people become able to see close up, middle, and distance without glasses.
Focusing at different distances
The CrystalensÔ behaves similarly to the way your natural lens did. It's not like wearing a pair of tri-focals, where you have to tilt your head to catch the right part of the lens. The CrystalensÔ automatically focuses on what you're looking at, whether it's a book you're reading, your computer screen, or traffic down the road.
What's the procedure like?
In one surgery, the cloudy natural lens can be removed, and through a very tiny incision, the rolled-up CrystalensÔ inserted. It unrolls itself and can be positioned exactly inside the membrane that used to encase your natural lens.
· It's an outpatient procedure and done with you lying comfortably on a bed
· In preparation, anesthetic eyedrops will be placed in your eye; they'll also dilate your pupil
· Perhaps medication will be given to help you feel calm
· A microscope is positioned over your eye and you'll be asked to look up into it and to hold still
· There's no pain, just a feeling of slight pressure
· It's over in about 20 minutes and a patch may be placed over your eye
· More eyedrops are used to prevent infection reduce inflammation and keep the pupil dilated
Recovery
You'll need someone to drive you home and you should rest till the following day, when there'll be a check-up appointment
· More eyedrops will be prescribed as your eye heals over the next week or so. They are to prevent your eye from changing focus and they make you sensitive to light. The CrystalensÔ needs to be correctly positioned as it heals, so for a week or two you may need to use reading glasses.
· Avoid any strenuous activities.
· Don't rub your eye.
· Within a day or two you'll notice improvement in your distance vision.
· The middle and near vision may be a bit blurred at first, but will improve in time, first the middle, then the near vision.
· Typically, you can return to work after 2 or 3 days, even though your vision is still a bit blurry
· Wear sunglasses when outdoors
· Don't use eye makeup for several weeks and avoid getting anything in your eyes like soap or shampoo, or the water from public swimming pools or hot tubs

After about 2 weeks, discontinue using any reading glasses, because you'll need to exercise and strengthen your focusing muscle. It could be a few months before it reaches its full ability to focus your eyes. Typically your eye surgeon will want to see you again in 2 to 4 weeks and at 3 to 6 months, then annually.

As your eyes heal, you might be surprised at how bright colors look and how intense lights can be, especially at night. And typically you'll need no glasses for either distance or reading.

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