# Why Do Nearsighted People Have Higher IQs? **URL:** \ **Category:** Factual Questions\ **Created:** [November 6, 2006, 3:07am UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246 "2006-11-06T03:07:24Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [November 6, 2006, 3:07am UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/1 "2006-11-06T03:07:24Z")
As I understand it, there is some link between scores on IQ tests and nearsightedness, with more myopic individuals receiving, on average, higher test scores. Is this accurate? What is the reason behind this association? Is there any evidence to suggest that reading/studying more causes nearsightedness?? Thanks. ---
**Author:** ![Sonia\_Montdore](https://avatars.discourse-cdn.com/v4/letter/s/90ced4/32.png) [@Sonia\_Montdore](https://boards.straightdope.com/u/Sonia_Montdore)\ **Post date:** [November 6, 2006, 3:20am UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/2 "2006-11-06T03:20:49Z")
[QUOTE=Surreal] As I understand it, there is some link between scores on IQ tests and nearsightedness, with more myopic individuals receiving, on average, higher test scores. Is this accurate? [/QUOTE] Cite? ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [November 6, 2006, 3:30am UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/3 "2006-11-06T03:30:18Z")
I never heard of this before, [but Wikipedia has](http://en.wikipedia.org/wiki/Myopia#Education.2C_intelligence.2C_and_IQ): > [@Wikipedia on Myopia](#): > > A number of studies have shown that the prevalence of myopia increases with level of education.[[32]](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=6830491)[[28]](http://www.blackwell-synergy.com/doi/abs/10.1034/j.1600-0420.2000.078006656.x#search=%22myopia%2C%20prevalence%22) > > Many studies have shown a relationship between myopia and IQ. According to Arthur Jensen, myopes average 7-8 IQ points higher than non-myopes. The relationship also holds within families, and siblings with a higher degree of refraction error average higher IQs than siblings with less refraction error. Jensen believes that this indicates myopia and IQ are pleiotropically related (both myopia and IQ are caused by the same genes). The mechanism that has caused a relationship between myopia and IQ is not yet known with certainty (Jensen, 1998). There is also the paper [“IQ and the Association with Myopia in Children”](http://www.iovs.org/cgi/content/full/45/9/2943) from The Association for Research in Vision and Ophthalmology, Inc. Dunno how respectable that organization is, but it’s another cite in support of the basic thesis: > [@](#): > > RESULTS. After controlling for age, gender, school, parental myopia, father’s education, and books read per week, myopia (spherical equivalent [SE]) of at least –0.5 D was associated with high nonverbal IQ (highest quartile) versus low IQ (lowest quartile) (odds ratio = 2.4; 95% confidence interval, 1.7–3.4). Controlling for the same factors, children with higher nonverbal IQ scores had significantly more myopic refractions (–1.86 D for children with nonverbal IQ in the highest quartile compared with –1.24 D for children with nonverbal IQ in the lowest quartile; P = 0.002) and longer axial lengths (24.06 mm versus 23.80 mm; P = 0.022). **Nonverbal IQ accounted for a greater proportion of the variance in refraction compared with books read per week.** (Emphasis mine.) Fascinating. For the record, I’m very much myopic. ---
**Author:** ![Sattua](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sattua/32/11906_2.png) [@Sattua](https://boards.straightdope.com/u/Sattua)\ **Post date:** [November 6, 2006, 3:31am UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/4 "2006-11-06T03:31:30Z")
Traditionally, more “intelligent” people have bad eyesight from doing a lot of reading in poor light. The diarist Samuel Pepys, for instance, gave up his diary because he couldn’t see the page to write. The advent of light bulbs should have ended this problem, though. ---
**Author:** ![susan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/susan/32/17537_2.png) [@susan](https://boards.straightdope.com/u/susan)\ **Post date:** [November 6, 2006, 3:35am UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/5 "2006-11-06T03:35:51Z")
My testable IQ is more than 2 SD above the mean. I am farsighted. Anecdote. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [November 6, 2006, 3:38am UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/6 "2006-11-06T03:38:35Z")
[QUOTE=Sattua] Traditionally, more “intelligent” people have bad eyesight from doing a lot of reading in poor light. [/QUOTE] I have to wonder about that. Not the intelligence part, but the idea that reading in poor light or “straining the eyes” makes the vision worse. Has this ever been proved? ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [November 6, 2006, 3:46am UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/7 "2006-11-06T03:46:15Z")
[QUOTE=Sattua] Traditionally, more “intelligent” people have bad eyesight from doing a lot of reading in poor light. [/QUOTE] In addition to **Sunspace** ’s objection, read the bolded sentence in the second quoted passage in my first post to this thread. Also, this passage from the same cite makes it even more explicit: > [@](#): > > CONCLUSIONS. Nonverbal IQ may be an independent risk factor of myopia, and this relationship may not be explained merely by increased reading (books per week) among myopes. **An interesting observation is that nonverbal IQ may be a stronger risk factor for myopia compared with books read per week.** The complexity of the relationships between nonverbal IQ, reading, and myopia warrant additional studies to clarify any cause–effect relationship. (Again, emphasis mine.) Books-per-week may be self-reported, however. I don’t know. I just don’t think that traditional explanation is borne out by the evidence I’ve seen so far. ---
**Author:** ![Sattua](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sattua/32/11906_2.png) [@Sattua](https://boards.straightdope.com/u/Sattua)\ **Post date:** [November 6, 2006, 4:41am UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/8 "2006-11-06T04:41:37Z")
True, I do not know that it has been proven that reading in bad light actually damages one’s eyesight. And notice that my little baseless anecdote was about the pre-Edison era, so it had nuttin’ to do with recent studies. ---
**Author:** ![edwino](https://avatars.discourse-cdn.com/v4/letter/e/35a633/32.png) [@edwino](https://boards.straightdope.com/u/edwino)\ **Post date:** [November 6, 2006, 4:59am UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/9 "2006-11-06T04:59:20Z")
[QUOTE=Derleth] …The Association for Research in Vision and Ophthalmology, Inc. Dunno how respectable that organization is, but it’s another cite in support of the basic thesis:(Emphasis mine.) Fascinating. For the record, I’m very much myopic. [/QUOTE] /nitpick. The cite you gave is from IOVS, a fairly respectable journal in the vision science world. The journal is published by ARVO, which is best known as throwing the largest conference for vision science every year in Ft. Lauderdale. My wife, who is in that field, says that the PI on that paper, Richard Stone, is well respected in the vision science world. And for the record, my wife, an optometrist with both an OD and a PhD, says that myopia is indeed associated with near work, of which reading is one. FTR, my vision dropped about a diopter after starting medical school, and that was not unusual amongst my classmates. ---
**Author:** ![WhyNot](https://avatars.discourse-cdn.com/v4/letter/w/c77e96/32.png) [@WhyNot](https://boards.straightdope.com/u/WhyNot)\ **Post date:** [November 6, 2006, 5:11am UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/10 "2006-11-06T05:11:56Z")
I am completely and utterly convinced that my nearsightedness was caused by my unceasing reading as a kid. (Which, in turn, was at least partially spurred by my high IQ.) The distance limit of my vision is exactly where I naturally hold a book in bed - about a hand’s breadth from the tip of my nose. \*\*Malienation \*\*pointed out in [this post](http://boards.straightdope.com/sdmb/showpost.php?p=7661964&postcount=6) (without cite, unfortunately) that nearsightedness may be heavily influenced by environment, not just genetics, as has long been believed. ---
**Author:** ![CC](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@CC](https://boards.straightdope.com/u/CC)\ **Post date:** [November 6, 2006, 5:33am UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/11 "2006-11-06T05:33:23Z")
[QUOTE=WhyNot] I am completely and utterly convinced that my nearsightedness was caused by my unceasing reading as a kid. (Which, in turn, was at least partially spurred by my high IQ.) The distance limit of my vision is exactly where I naturally hold a book in bed - about a hand’s breadth from the tip of my nose. \*\*Malienation \*\*pointed out in [this post](http://boards.straightdope.com/sdmb/showpost.php?p=7661964&postcount=6) (without cite, unfortunately) that nearsightedness may be heavily influenced by environment, not just genetics, as has long been believed. [/QUOTE] So in this conceptualization, high IQ leads to nearsightedness. Is that the hypothesis that we are to suppose is the leading one? I haven’t seen a post that posits that nearsightedness leads to high IQ, have I? And we see that Jensen posits that both are caused by another agent. And there are limited studies that show the correlation in the first place. This sounds like a job for Cecil - sorting out the claims and the evidence; sorting out correlation from causation. And if not the Man, Himself, then someone who looks just like him. FTR - I could barely read what you all were posting until I got a lot closer to the computer. ---
**Author:** ![susan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/susan/32/17537_2.png) [@susan](https://boards.straightdope.com/u/susan)\ **Post date:** [November 6, 2006, 6:47am UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/12 "2006-11-06T06:47:43Z")
Whereas I had to hold the computer farther away! Shoshana, who read thousands of books as a teen and only grows ever-more farsighted ---
**Author:** ![ParentalAdvisory](https://avatars.discourse-cdn.com/v4/letter/p/53a042/32.png) [@ParentalAdvisory](https://boards.straightdope.com/u/ParentalAdvisory)\ **Post date:** [November 6, 2006, 7:05am UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/13 "2006-11-06T07:05:23Z")
Isn’t nearsightedness associated with the physical size/distortion of the eye, and not by how much one reads? There are many people with -3.00 D+ vision that likely weren’t avid readers as children/young adults. What about 20/20 folks that did read frequently and maybe in poor lighting that don’t have nearsightedness but above average IQ? My own theory. No need to take it seriously because I just thought about it: My theory is that individuals have a physical predisposition to nearsightedness regardless of “near work” activity. And that any correlation to higher IQ is a result of isolation by peers due to corrective lenses early in childhood due to stigma. Isolation would then lead to frequent reading (but not limited to), and other curricular activities that would enhance IQ in learning environments rather then social enviroments. Hey, if you’re the four-eyed dork that didn’t get invited to hang out or go to parties, what would you do? Probably learn more then socialize. Not that everybody that had glasses got picked on, but the ones that did may have skewed the results for more IQ in the myopia category, maybe? Over the years, those points might add up. A lot generalizations here, but there ya go. ---
**Author:** ![FRDE](https://avatars.discourse-cdn.com/v4/letter/f/e68b1a/32.png) [@FRDE](https://boards.straightdope.com/u/FRDE)\ **Post date:** [November 6, 2006, 7:51am UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/14 "2006-11-06T07:51:39Z")
Computers are also pretty good for shafting the eyesight. ---
**Author:** ![Mister\_Rik](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mister_rik/32/491_2.png) [@Mister\_Rik](https://boards.straightdope.com/u/Mister_Rik)\ **Post date:** [November 6, 2006, 8:34am UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/15 "2006-11-06T08:34:15Z")
[QUOTE=Sattua] The advent of light bulbs should have ended this problem, though. [/QUOTE] Not necessarily. When I was a little kid, I hated going to bed. But my mom strictly enforced “bedtime” and made me turn out my light and “go to sleep” (one of these days I’ll learn the magical word that allows a person to simply fall asleep on command). I usually wasn’t ready to go to sleep, and so I would lay a book on the floor in the little sliver of light coming in through my slightly open bedroom door, and read until my parents went to bed themselves and shut off the hall light. Pretty poor lighting for reading! Didn’t seem to hurt my eyesight, though. I was 38 or 39 before I bought my first pair of reading glasses. ---
**Author:** ![Khadaji](https://avatars.discourse-cdn.com/v4/letter/k/9e8a1a/32.png) [@Khadaji](https://boards.straightdope.com/u/Khadaji)\ **Post date:** [November 6, 2006, 12:44pm UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/16 "2006-11-06T12:44:36Z")
More anecdotal evidense: Terribly near-sighted and a huge reader all my life. ---
**Author:** ![Si\_Amigo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/si_amigo/32/2877_2.png) [@Si\_Amigo](https://boards.straightdope.com/u/Si_Amigo)\ **Post date:** [November 6, 2006, 2:33pm UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/17 "2006-11-06T14:33:28Z")
I’ve had lasik to correct my eyesight. Will my IQ start to drop. I hope not, because I don’t want to go to Iraq. ---
**Author:** ![Oregon\_sunshine](https://avatars.discourse-cdn.com/v4/letter/o/50afbb/32.png) [@Oregon\_sunshine](https://boards.straightdope.com/u/Oregon_sunshine)\ **Post date:** [November 6, 2006, 3:12pm UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/18 "2006-11-06T15:12:46Z")
> [@Shoshanna](#): > > My testable IQ is more than 2 SD above the mean. I am farsighted. Anecdote. Same here. ---
**Author:** ![Harriet\_the\_Spry](https://avatars.discourse-cdn.com/v4/letter/h/e56c9b/32.png) [@Harriet\_the\_Spry](https://boards.straightdope.com/u/Harriet_the_Spry)\ **Post date:** [November 6, 2006, 3:46pm UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/19 "2006-11-06T15:46:07Z")
[QUOTE=Phase42] Not necessarily. When I was a little kid, I hated going to bed. But my mom strictly enforced “bedtime” and made me turn out my light and “go to sleep” (one of these days I’ll learn the magical word that allows a person to simply fall asleep on command). I usually wasn’t ready to go to sleep, and so I would lay a book on the floor in the little sliver of light coming in through my slightly open bedroom door, and read until my parents went to bed themselves and shut off the hall light. Pretty poor lighting for reading! [/QUOTE] I would actually read by the light of my LED calculator, which I was smart enough to know to punch in all 8s to maximize the amount of light. ---
**Author:** ![Tibby](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tibby/32/17030_2.png) [@Tibby](https://boards.straightdope.com/u/Tibby)\ **Post date:** [November 6, 2006, 6:20pm UTC](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246/20 "2006-11-06T18:20:02Z")
Here’s another WAG: _It’s evolutionary, my dear Watson._ Our myopic ancestors, not seeing predators from afar, needed smarts to evade danger that was up close and personal. Natural selection took care of our intellectually stunted and short-sited forbearers. They survive now only in the coprolites of ancient predators. [Next page](https://boards.straightdope.com/t/why-do-nearsighted-people-have-higher-iqs/379246.md?page=2)