not so new eyes with resto lens

[Jls]

Just had cataract surgery and had the Restor lens put in with a piggy back lens because of my high astigmism(sp). I now see halos some during the day and around most lights at night. The Dr tells me this will improve but what I have been reading is they do not. If he has to remove them then what is my risk then and is the doctor right. He is one of the best in our area and I want to be lieve him because they are get but I can not drive at night and with my acitive life style this going to be a burden on my family.

[CataractExpert]

Halos can be caused when light entering the eye is out of focus. The focus blur presents as halos. Someone who is myopic (nearsighted, shortsighted) can easily create halos by simply removing their corrective lenses and looking at a well-lit object. As that object is brought near until it is in focus, the halos dissipate until they are gone.

In daylight halos tend to present as poor vision quality. Halos tend to be more noticeable at night because the light blur is expanded into darkness. Light on dark is almost always more noticeable.

To understand how the ReSTOR and other multifocal intraocular lenses (IOL) work and how your vision quality can improve, we need to talk about refraction and optics. All IOLs bend light to create a focal point; this is called refraction. Optics provide a range of focus of that bent light.

A good example of optics is when a photograph has perfect focus on a person's face, but the mountains in the background are blurry. The optics of the camera are set for the close distance to the person, not to the far distance of the mountains. Cameras are able to adjust the optics by changing the distance between lenses, but the ReSTOR IOL is not able to make these kinds of changes.

A conventional single-focal IOL has optics for one distance and usually the surgeon will recommend optics for distance vision (20 feet to infinity) and the patient will use reading glasses to see objects near. A multifocal IOL uses a portion of the IOL for distance optics, a portion for mid-distance optics, and a portion for near optics. The potential advantage of the ReSTOR is a reduced need for reading glasses because near, mid, and distance objects can be in focus, but all multifocal IOLs are limited.

A monofocal IOL bends all light for one optic range. That means that 100% of the light entering the eye is in focus for that particular optic range. This provides the highest possible vision quality for that optic range, which is usually distance vision.

The ReSTOR bends light for multiple optic ranges. Just for an example, let's say that the ReSTOR will focus 25% of light for near objects, 60% of light for distant objects, and 15% of light for mid-range objects. That means that if you are looking at an object that that is near, 25% of the light is focused near, but 75% is not. If you are looking at an object at mid-range, 15% of the light is focused at mid-range, but 85% is not. If you are looking at an object that is distant, 60% of the light is in focus and 40% is not.

At the beginning of this post I pointed out that halos are caused when light entering the eye is out of focus. As you can see, depending upon the distance of the object you are looking at, a significant portion of the light passing through the ReSTOR lens and entering the eye can be out of focus. If all of the light were out of focus, halos would be large and vision quality would be poor. Since at least some of the light passing through the ReSTOR is in focus, halos are moderated.

These numbers are rough estimates, but the ReSTOR does have less light for mid-range optics. This is why with the ReSTOR you can see clearly the can of beans in your hand, your car in the parking lot, but the items on the shelves at your grocery store are not so easy to see. You have probably noticed that halos are greater or lesser depending upon the distance of the object. Now you know why.

Several small studies have shown that the halos caused by multi-focal intraocular lenses like the ReSTOR can improve with time. Improvement is not due to healing or even changes in the IOL. Improvement is due to the brain learning how to deal with the multifocal the lens.

The brain can adapt to learn to “ignore” the light that is out of focus. This may seem odd, but the brain is very good at ignoring bad information. An excellent example is the blind spot. All of us have a very large spot in our field of vision that is totally blind. This spot is located where the optic nerve enters the eye and is attached to the retina. Even though we have this blind spot, we don’t “see” it. That is because the brain has learned to ignore the blind spot and “look around” it. Similarly, the brain can learn to “look around” the effects of a multi-focal IOL like the ReSTOR. This is called neural adaptation.

It is impossible to know how much your brain will learn to adapt and some people never achieve satisfactory multi-focal vision. What I suggest is that you discuss with your doctor a clear plan of action. Decide at what point in time or at what point in events (such as ndYAG capsulotomy) you would need to decide if the ReSTOR should be removed, and then wait until that point to make a decision. The more time you give your brain to adapt to the ReSTOR lens, the better.

The operation to exchange the ReSTOR multi-focal lens for a single-focal lens is very similar to your cataract surgery, however the surgeon is not required to break-up and remove your old cataractous natural lens. This means that the process will be much faster and with less trauma to the eye.