presbyopia

Lil' Wayne and cataracts

"You can't see me baby boy, you got them cataracts" - Lil' Wayne in Best Rapper Alive

Who said rap music is bad for you? I think its educational! Lil' Wayne may not know exactly what a cataract is, but he definitely has the right idea.

A cataract is the clouding of the lens that is inside the eye. As the lens becomes more clouded, vision becomes blurred due to light being blocked or scattered. This is the same lens that we use to focus at near objects. The same lens that stops working around the age of 45 and forces people to start wearing reading glasses (See: presbyopia in the "All Kinds of Blurry" post).

Everyone will develop cataracts at some point in their lives if they live long enough. How much and how fast depends on the individual and the environment. Medical conditions like diabetes can cause cataracts to develop faster. Sunlight is the main environmental factor. So, grab those sunglasses!

Congenital cataracts - It is possible to be born with a cataract. I recently saw a 5 year old boy who had a cataract in one eye. Another reason why kids should have regular eye exams.

Traumatic cataracts - Getting hit in the eye can cause a cataract. Wear protective lenses whenever possible!

How do you treat cataracts?

The only treatment is removal. The cloudy lens is removed and new clear plastic lens is inserted in its place. The surgery takes about 10-15 minutes per eye and requires an incision less than half a millimeter in size!

Who knows, maybe next week Kanye West will rap about Macular Degeneration... Stay posted!

 

"I spent a G on these frames, but my vision is priceless" - Lil' Wayne

 

All kinds of blurry

In my very first post I wrote a little about myopia, which is near-sightedness. Here we'll discuss all the other "-opias" and "-isms" that can make your vision blurry. They are generally referred to as "refractive errors".

A quick review of Myopia. It is due the eye being longer than average. So, rather than an image being focused right on the retina, it falls a little short. Of course, this gives us blurry vision for distant objects which can be corrected with "minus" prescription glasses and contacts, or laser surgery. Example of near-sighted prescription is: -3.25.

 

Hyperopia. This is what we call far-sightedness. As you would expect, a hyperopic person would have more trouble with near and less trouble with distance. This is a result of the eye being a little bit shorter, thus images fall behind the retina. This is corrected with "plus" prescriptions. Also can be corrected with laser.

 

Astigmatism. Is not affected by the length of the eye. Astigmatism is a result of the shape of the front of the eye (the cornea). With astigmatism, the cornea is not perfectly round, it is a little steeper in one direction than the other. The common analogy is a basketball compared to a football. So, light cannot be focused to one point on the retina. It is split by the different curves of the cornea. To correct this, the prescription needs two powers (one for each curve of the cornea). An example of this would be -1.50 -0.75 x180. The "-0.75" is the astigmatism part of the prescription and "x180" shows that this prescription needs to be placed at 180 degrees. Astigmatism can be corrected with glasses, contacts, and laser.

 

Presbyopia. The first three refractive errors are mostly hereditary. The last one, however, is purely age-related and happens to everyone. As we age, the accomodative system (system inside our eyes that helps us focus at near) slowly stops working. Eventually, as we make it through our 30s into our 40s, we notice that things up close are not as clear as they used to be. Often, patients will say that they need to hold reading material further away. And eventually no matter how far away you hold it, its just not clear enough! Correction usually involves reading glasses, bifocals, or multi-focal contact lenses. Laser surgery is not a very useful option because it does nothing to improve the accomodative system.