Nearsightedness Increasing in U.S.

[The Straight Story]

Nearsightedness Increasing in U.S.


It looks like nearsightedness is on the rise in the United States.

Researchers tapped into a wide-ranging health survey to rate vision in the population in the early 1970s and roughly 30 years later. They compared eyesight information for more than 4,400 people tested in 1971 and 1972 with data from another set of 8,300 people tested from 1999 to 2004.

sciencenewsThis broad survey showed that 25 percent of those examined in the early 1970s were deemed to be nearsighted, compared with 42 percent examined three decades later, the researchers report in the December Archives of Ophthalmology. That’s an increase of 66 percent.

Myopia severity also increased, with moderate nearsightedness doubling between the two time periods and severe cases, although uncommon, also rising sharply. Mild myopia cases increased slightly, from about 13 percent to 18 percent. This group included some people who did not need corrective lenses, says study coauthor Susan Vitale, an epidemiologist at the National Eye Institute in Bethesda, Md.

Among blacks, the overall myopia rate was lower than in whites but still jumped from 13 to 34 percent over the three-decade span.

http://www.wired.com/wiredscience/2009/12/nearsightedness-increasing/

[ChairmanAgnostic]

1. that explains Bush's election, but

how does that explain Lieberman's win?

[dysfunctional press]

2. maybe that's why so few people seem to be able to take the long view of things?

and only focus on the here and now?

[Freddie Stubbs]

3. Probably due to Internet porn

[we can do it]

4. So Is Stupidity

[Romulox]

5. I call BS. I wasn't given my first pair of glasses until I was a teen

But I sure as hell needed them before that. I think there was simply less awareness of the issue when I was small.

[surrealAmerican]

7. This was not a survey of who wears glasses.

They actually examined the study participants to determine nearsightedness. Had you been a participant when you were a child, they would have noticed you were nearsighted.

That said I wonder why there would be such a big increase. Perhaps their samples were not as random as they should have been.

[Romulox]

8. That's not what the article says...

Researchers tapped into a wide-ranging health survey to rate vision in the population in the early 1970s and roughly 30 years later. They compared eyesight information for more than 4,400 people tested in 1971 and 1972 with data from another set of 8,300 people tested from 1999 to 2004.

This broad survey showed that 25 percent of those examined in the early 1970s were deemed to be nearsighted, compared with 42 percent examined three decades later, the researchers report in the December Archives of Ophthalmology. That’s an increase of 66 percent.

There is no claim that all the subjects were actually tested for near-sightedness, but rather that a certain percentage of them were "deemed to be nearsighted"--presumably after some smaller sub-set was selected for actual vision testing--i.e. by actually observing the eye through an optical refractor.

[fishnfla]

10. No thats not how it works

there are other vision problems besides being nearsighted
a certain percentage are emmetropic (normal vision)
a certain percentage are hyperopic (farsighted)
a certain percentage are astigmatic (astigmatism)
a certain percentage are nearsighted (myopic)

when they say deemed they mean they were determined to be in one of the above groups (not that hard to do)

so of the sample with vision problems ( the last 3), they determined that the percentage of those that are nearsighted ( vs the other 2 ametropias and the emmetropes) has increased

the poster is right the study may be biased due to samples or testing methods.

the usual rule of thumb i always heard was 30% give or take of the population is nearsighted

edit: clarity

[Romulox]

11. Without discussing the METHODS, you're just restating your own assertion...

There is no assertion that either of these groups was "tested" for eye defects by any objective criteria--it says they were "deemed" to be nearsighted.

"when they say deemed they mean they were determined to be in one of the above groups "

Right, but the question is how were they "determined to be in one of the above groups"? There is no indication that they were "deemed" to be nearsighted after observation of their eyes through optical refraction.

So my observation stands: I was "deemed" to not need glasses for many years, and in error. I didn't "develop" nearsightedness at a later date--it simply wasn't discovered.

[fishnfla]

13. I jave been an eye Dr for 22 years. I've seen dozens of these studies

They are determining the distrubution of refractive error in a set population.

EVERY SINGLE TEST SUBJECT HAS A REFRACTION OR A SERIES OF REFRACTIONS DONE OVER A PERIOD OF YEARS.(this is the answer to your question) This is the test data. They collect it through comprehensive eye exams, I've known collegues who participate in these studies. They have to "deem" or classify the subjects based on the clinical data. They have to have eye exams to eliminate pathological causes of reduced vision. It is eyeglass, or refractive, information only.

Subjects who are + 1.00 diopter or greater in spherical power are deemed to be farsighted
those with -1.00 diopter of cylindrical power or more are deemed to be astigmatic
those with -1.00 diopter or more of spherical power are deemed to be nearsighted

some studies use lower #'s in their classifications. This is a point of contention-see below may apply to you

The article does not delve into this clinical data at the risk of boring evryone besides nerds like me. It merely mentions "eyesight information" But take it from me, the NEI geeks are strict in their guidelines.

You are getting hung up on the words "deemed" vs "developed". I think you are trying to apply your tree and missing the whole forest. The article gets into the contentious points when they talk about mild myopia and the subjects who have a refractive error but dont need glasses-perhaps this applied to you, its kinda subjective grey area

[fishnfla]

6. longstanding argument: nature or nurture?

probably both

[Zoeisright]

9. Humans are thwarting evolution in many ways.

Mostly through modern medicine. Eyeglasses are just one way. Those with poor eyesight wouldn't have been in the gene pool without intervention.

[Spike89]

12. Not so much...

Granted, severe congenital vision problems probably wouldn't have allowed gene survival in prehistoric times. However, even somewhat serious vision problems probably weren't fatal in a high enough percentage of cases to preclude mating (remember, mating age in "pre-civilization" was probably even lower than 12 years old.

Likewise, poor dental genes might mean that your prehistoric relatives didn't live much longer than their teeth, but as long as they made it about 20 years, it wouldn't make much evolutionary difference.

It's highly unlikely that human precursors were not social creatures at least millions of years back...social systems greatly affect evolutionary traits. For instance, in a clan with "poor" eyesight in general, a couple of lookouts with better eyes can keep the entire group safe. If the average eyesight drops too far, it can affect the survival rate for the group, but survival (in evolutionary terms) would be affected little by vision problems that manifest only after age 20 or so.