PDA

View Full Version : Why do so many peoples' eyes go bad?


hauss
03-30-2003, 11:51 PM
Why does practically everyone have eye problems? Evolution brought us so far, but without specs of some sort, we could never survive hunting and gathering. What's the deal? Everything else works on our bodies...... not one body part that I can think of wears out so quickly and helplessly.

Has it always been like this, hundreds of years ago or is this i new trend?

Bob55
03-30-2003, 11:59 PM
Not everyone has eye problems. Also, the majority of people are hyperopic which means they're farsighted, and usually won't have problems until they get older. A lot of problems are brought on by the constant near work that we do (reading), which probably wasn't too common back in our hunting & gathering days.

Everyone will develop presbyopia (can't read up close anymore around age 40) because we lose our focusing ability as we age. Again people probably didn't live too much beyond their 40s back in the day.

Yllaria
03-31-2003, 12:03 AM
You only have to live long enough to reproduce.

And for me it's the teeth and the knees that are going. Without modern dentistry, I'd bet most thirty year olds would be starting to shed molars. I'm guessing that wisdom teeth were originally used as spares. But then I'm not an evolutionist, nor do I play one on TV.

shijinn
03-31-2003, 12:50 AM
it's my WAG that our eyesights are getting poorer because good eyesight is no longer important in choosing a mate - if you don't like one with specs there are always contact lenses; so evolution is helpless here..

bibliophage
03-31-2003, 01:42 AM
If you're talking about the rate of myopia (nearsightedness), it does appear that the rate is higher now than it used to be. The cause is almost certainly environmental, but the exact culprit is not known with certainty. Cecil Adams discusses the issue in his column on Will sitting too close to the TV, reading with bad light, etc., ruin your eyes? (http://www.straightdope.com/classics/a5_105.html)

A1C Joe
03-31-2003, 02:54 AM
Too much SDMB.

David Simmons
03-31-2003, 02:59 AM
Originally posted by Yllaria
You only have to live long enough to reproduce.



Bingo as far as evolution is concerned.

I just went to the ophthalmologist to see about my macular degeneration. He informed me that I have the relatively benign "dry" variety which progresses slowly. He went on to say that for my age I have good vision (corrected 20/20 right, 20/25 left) and it should stay that way as long as necessary.

So I said, "You mean it's a race?"

And he changed the subject.

Snooooopy
03-31-2003, 04:11 AM
I think it's all the people masturbating for peace (http://masturbateforpeace.com/).

Broomstick
03-31-2003, 06:04 AM
It's partly how you define "bad"

At present, we have this specific number everyone is "supposed" to be at, called 20/20.

Prior to that, and prior to the invention of spectacles, writing, etc. people could probably be 20/30, 20/40, 20/10, and so forth and never really know their vision wasn't "perfect". As long as vision was good enough for them to spot the tiger or find food it reallly was good enough. Someone with slightly worse vision might wellll survive by paying attention to how folks with better vision were reacting around them.

So folks have probably always had slightly variable sorts of vision without realizing it.

istara
03-31-2003, 07:51 AM
Originally posted by Bob55
Not everyone has eye problems. Also, the majority of people are hyperopic which means they're farsighted, and usually won't have problems until they get older. A lot of problems are brought on by the constant near work that we do (reading), which probably wasn't too common back in our hunting & gathering days.
Interestingly and ironically, my former optician told me that the most myopic patient he ever had - to the point of verging on partial-sightedness - was a shepherd. Someone whose job, day in day out, is about long distance vision. Poor guy!

The Scrivener
03-31-2003, 11:59 AM
Modern lifestyles and our (basically laudable) emphasis on education have a profound impact. Intensive reading at an early age is well-known as an instigator to near-sightedness (myopia). It's no coincidence that in any school, there is a correlation between nerdiness and wearing glasses.

[I read years ago about a research study of the causes of myopia, in chicks (the poultry kind). The chicks were raised in a modified environment in which their eyes were only allowed to focus on very short distances -- as if to simulate learning how to read. The result: widespread myopia in the chickens!]

Another set of lifestyle factors is more ominous to our long-term opthalmological health, however. Diabetes, obesity, smoking, inactivity, poor diet, and cheap, non-UV-blocking eyeglasses variously contribute to blindness, cataracts, and other serious eye problems, whether directly (diabetes) or indirectly (strokes that result in blindness or partial blindness).

Is anyone informed on the long-term risks (if any) related to electromagnetic radiation, etc., of sitting in front of a computer monitor all day?

Revtim
03-31-2003, 12:17 PM
Originally posted by The Scrivener
Modern lifestyles and our (basically laudable) emphasis on education have a profound impact. Intensive reading at an early age is well-known as an instigator to near-sightedness (myopia). It's no coincidence that in any school, there is a correlation between nerdiness and wearing glasses.
An optometrist I used to go to supported this theory.

j.c.
03-31-2003, 12:18 PM
I have no science here, just one little story. When I was a sprout, many of the poor black children at my school asked me, regularly, "Why do white poeple have such bad eyesight? White people always have glasses. You never see us with glasses." Then we got to the grade before middle school, they gave us all the standard in-school eye test, and of course many of the poor black children had poor eyesight.

Broomstick makes a good point, until widespread standardized eye testing, we didn't have data on vision. Additionally, in the past, many things, such as disease and injury, caused eye damage so when we read about someone with bad vision, we may not know if that person was simply nearsighted or lost their vision for another reason.


(FYI, the non-poor black children had adeqaute health care. And there were probably poor white children who tested badly, but because they hadn't been bugging me for years, their diagnosis didn't stick in my mind.)

MLS
03-31-2003, 03:14 PM
It's no coincidence that in any school, there is a correlation between nerdiness and wearing glasses.

I think there's a potential positive feedback loop there as well. If you can't see distances very clearly, you're more likely to keep your nose in a book instead of (for example) playing baseball, resulting in insufficient exercise to the distance-focusing eye muscles, which further impairs your ability to see distances clearly. And then there's a possible further reinforcer as the nearsighted bookworm who always strikes out is last chosen for the team all the time, and so comes to avoid the rejection associated with such activities, and stays inside with his nose in a book. Not getting as much exercise as his contemporaries, he becomes even worse at sports, and avoids them even more. And so on. We won't even mention sadistic Phys. Ed. teachers.