When Shakespeare's King Lear calls on "cataracts" to spout during his "Blow winds, and crack your cheeks!" speech, he's not asking for cloudy vision.
In Shakespeare's day, a "cataract" also meant a huge waterfall.
This is fitting, because the clouds of white foam arising from a waterfall are metaphorically like the cloudy vision caused by a cataract.
Roughly half of everyone who lives to age 80 will eventually get cataracts in one or both eyes.
Live to age 95, like the great San Francisco poet and City Lights bookstore owner Lawrence Ferlinghetti, born March 14, 1919, and you'll have close to a 100-percent chance of getting cataracts.
But that's a small price to pay for such awesome longevity.
What exactly is a cataract? To answer that question, let's begin by looking at the eye.
A cataract is a clouding of the eye's lens.
On the picture, do you see where the lens is in the eye? Yes, right behind the pupil.
Light enters the eye through the pupil.
As the picture shows, the lens focuses light onto the retina, which is a layer of light-sensitive cells at the back of the eye.
The lens must be clear to focus light onto the retina.
If the lens has become cloudy with a cataract, the image you see will be blurry.
People say that having a cataract is like looking through a dirty car windshield.
Now let's look at how cataracts form.
The eye's lens is composed of two substances.
The first is water.
The second is protein.
As we age, some of the protein that constitutes the eye's lens (along with water) can clump together, causing the clouding of the lens.
Although most cataracts are simply a product of aging, there are other causes of cataracts, too.
Diabetics can develop cataracts.
So can steroid users.
Cataracts can develop after an eye injury, sometimes years later.
Sometimes babies can be born with cataracts.
Cataracts can develop after exposure to radiation.
Other factors that could cause cataracts include those common bugaboos smoking and drinking.
Here are the symptoms of cataracts, in case you think you might have one.
Cloudy or blurry vision.
Colors look faded.
Glare from headlights, lamps or sunlight bother you more than it used to.
You may also see halos around lights.
Other symptoms could include double vision or multiple images in one eye.
Frequent changes in your prescription for eyeglasses or contact lenses could also be a sign of cataracts.
If you notice any of these symptoms, or if you are age 60 or older, ask your eye doctor to check your eyes for cataracts, as well as for age-related macular degeneration, glaucoma, or any other vision issues during your next eye exam, which should be soon.
If you do have a cataract, and it's interfering with your normal, everyday activities, such as driving, reading, or watching TV, your cloudy lens can be removed in surgery and replaced with a clear, artificial lens.
If you need cataract surgery in both eyes, usually the doctor will do each eye a month or two apart.
However, surgery should be avoided unless it's absolutely necessary for your vision, or if a cataract interferes with getting another eye issue treated, such as age-related macular degeneration or diabetic retinopathy.
Nevertheless, cataract removal is one of the most common operations performed in the United States, and about 90 percent of people who have cataracts removed have improved vision.
Now if you don't have cataracts and you want to forestall getting them, there are some precautions you can take, according to research done by staffers of the Mayo Clinic.
Get regular eye exams, at least once every two years, or more frequently if you notice changes in your vision.
Quit smoking and drinking alcohol.
We like this old joke, "If I'd known I was going to live this long, I'd have taken better care of myself.
" But in reality, most smokers and drinkers won't live to 100.
Wear sunglasses and clear glasses with 100% Ultraviolet (UV) protection.
Maintain a healthy weight.
Eat plenty of fresh fruits and vegetables.
The latter finding is buttressed by research performed at the University of Oxford, the results of which were published in 2011 in the American Journal of Clinical Nutrition.
The study found that the risk of getting cataracts was greatest for high meat eaters (those who ate more than 3.
5 ounces of meat each day).
It decreased from each dietary group to the next, in this order: moderate meat eaters, low meat eaters, fish eaters (people who eat fish but no other meat), vegetarians, and vegans.
In fact, the risk for vegans was roughly 40 percent lower than for the high meat eaters.
Dark green leafy vegetables such as spinach and kale, both of which contain the antioxidant-carotenoids lutein and zeaxanthin, are associated with significantly lower risks of cataracts.
So, quit smoking, decrease or eliminate drinking alcohol, decrease or eliminate eating meat, increase eating fruits and veggies, and you might live long enough to have your first cataract as a 95th birthday present - among other goodies!