The causes of myopia

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Cartoon in China Daily (7/5/19):

Cellphones may well have exacerbated the problem of epidemic myopia in the Sinographic sphere, and especially reading and writing the densely structured, tiny characters on small screens puts a tremendous strain on the eyes, but nearsightedness was already a serious problem in the Sinosphere long before cellphones were invented.


"Chinese characters and eyesight" (11/12/14)

"An Eighteenth-Century Japanese Language Reformer" (4/23/15) — fascinating comments on the Sinographic writing system and comparison with alphabetic writing in India and Holland.  "Only China concocted a cumbersome system, so things are disorderly there and everything is troublesome."  An argument for writing in kana.

"Sinophone and Sinosphere" (11/8/12)

"The Sinophone" (2/28/19)

"Writing Sinitic languages with phonetic scripts" (5/20/16)

"Writing characters and writing letters" (11/7/18)

"Learning to write Chinese characters" (7/29/17)

"Writing Chinese characters as a form of punishment " (11/1/15)

"Copying characters" (2/11/13) — begins with a photo that brings tears to my eyes

"The cost of illiteracy in China" (3/31/12)  — The strained look of the little girl in the photograph accompanying the post speaks volumes! One often sees exactly that look (note especially the pinched brow) on the faces of children (and even adults!) who are trying to extract sounds and meanings from the densely packed, complicated strokes of the morphosyllables on a page. This is not to mention that the texts children are asked to read at a young age are poorly written, employ an execrable style (too wooden and grown-up, semivernacular-semiclassical, etc.), and are on dull subjects that are completely inappropriate for elementary and middle (junior high) school pupils.

[h.t. James Fanell]


  1. Antonio L. Banderas said,

    July 5, 2019 @ 7:30 pm

    Another point for Pinyin.

  2. John Rohsenow said,

    July 6, 2019 @ 2:29 am

    Don't know if it was true or not, but I recall a scene in THE LAST EMPEROR film when his English tutor recommended glasses, and the palace eunuchs, etc. said that they would not be suitable for an emperor; the optometrist replied, "then you will have a blind emperor."
    I believe later photos showed him with glasses, like the Dali Lama today,
    another historical figure with a foreign tutor.

  3. Vilinthril said,

    July 6, 2019 @ 4:55 am

    The last time I tried to do some research, I was under the impression that the best theory so far was lack of exposure to sunlight, so I doubt smartphones had a further negative effect beyond the spread of (reading and) PCs …

  4. Marlo said,

    July 6, 2019 @ 1:33 pm

    Please do not be quick to attribute myopia to Chinese characters without sufficient evidence. Myopia is more common among Asian Americans as well as Singaporeans. I'm not an optometrist, but last I checked, it was thought to be due to lack of exposure to sunlight as well. Makes sense given the Asian emphasis on studying instead of sports. But I would not be surprised if there was a genetic component as well.

  5. Alex said,

    July 6, 2019 @ 6:10 pm

    Eyesight definitely is a big focus issue here for parents.

    Im not a medical professional but I imagine perhaps its about constantly looking at things closely.

    Anyway about here. I nearing 50 and have worn glasses or contacts since 3rd grade.

    Its definitely easier reading smaller English words than Chinese.

    On another point this extreme focus on protecting eyesight seems to be the most super extreme with the current grandparents generation. The current parental generation is just extreme.

    It goes so far as not wanting kids to use educational apps or watch good tv or programs on tablets.

    I feel this has to do with historical issues such as over worry about cold and lack of availability of glasses. The way shenzhen people bundle up here in the autumn is insane. Perhaps catching a cold meant death back then so the extreme worry are going through what i call generational half lives.

    When I recommend to parents the best way for their kids to learn English is to watch good shows like Arthur they go dont you worry about your kids eyesight? I always laugh and say I don't think I wish my kids to grow up being hunters. I also feel that advances in science will totally wipe out nearsightedness within 20 years.

    So I feel id rather kids learn more when young as a trade off versus potential near nearsightedness.

    I tell them im at minus 800 (scale used here) and they are shocked as they have never seen me with glasses as day to day I use contact lenses.

    Another aspect is how many people tried to tell me how dangerous it is to let my son almost 11 to use contact lenses. He likes them for tennis and swimming.

    I had to show them (google is great) pdfs on the average age kids start using contact lenses in the West.

    I can go on about the many what I call legacy half life beliefs here. They really are half lives as I see change withing the younger generation especially in regards to having ice in drinks or eating ice cream before 5.

  6. Doctor Science said,

    July 6, 2019 @ 6:38 pm

    A quick look in Google Scholar shows that the myopia rate is extremely high in Korea, too, even though hangul is very clear and simple compared to Chinese script. I conclude that the script contributes very little to myopia, a culture of (indoor) study contributes a lot. Similar, very high rates of myopia are also seen in male Israelis from ultra-Orthodox schools, which suggests that genetics is also not a dominating factor.

  7. Alex said,

    July 6, 2019 @ 7:13 pm

    I believe the eye "muscles" get used to looking at things closely, than far, so reading of any kind the more you do the greater the chance of increasing near nearsightedness and that combined with genetics.

    Im sure there must be studies of amount of reading and homework versus less.

  8. Victor Mair said,

    July 6, 2019 @ 8:42 pm

    For those who dismiss the possibility for any causal relationship between the nature of Chinese characters and the epidemic rates of myopia in China, I suggest that they read carefully the whole of the first item in the "Readings" section of this post, including the necessity for much greater amounts of nearwork, inside (out of the sun) work, and eyestrain to master them.

    It wouldn't hurt to read the other referenced items too. This is not a new topic dreamed up by the China Daily, but one that has plagued China already before the founding of the PRC.

    The average number of strokes for commonly used characters is about twelve. In typical fonts, it becomes difficult to distinguish the individual strokes for characters with that number of total strokes (e.g., 握, 董, 葡). As the number of strokes increases, it becomes progressively more difficult to distinguish the individual strokes (e.g., 16 薯, 18 鹰), until by around 22 囊 characters having that number of strokes become black, blurred blobs at normal font size. Even with characters having only a few strokes, it is often necessary to strain to distinguish them from characters with a similar appearance.

    Naturally, on cell phones with their tiny screens the challenges to differentiating the thousands of characters that must fit in the same size small squares becomes all the greater.

  9. Andrew Usher said,

    July 6, 2019 @ 10:09 pm

    There is definitely something to the idea that the eyes accommodate to their typical use, and that that is clearly a contributor to myopia. I went through grade school wearing sronger and stronger glasses, until I resolved against everybody's advice to stop wearing them regularly. My vision then partially reversed, and has stabilised with my relaxed focus very nearly at typical reading distance, which is how I like it. Based on that experience itself, I would not wish children to use (infinity-corrected) glasses continually, nor contact lenses, inherently continuous.

    So (and in agreement with previous comments) characters themselves don't cause myopia, but the greater amount of very close work their mastery requires probably does. I don't consider myself to have a real stake in the issue, but I've always considered the Chinese writing system (and their continued adherence to it despite knowledge of the alphabetic principle) to be ridiculous. The positive that I see is that it prevents Chinese from being a serious rival to English as global language, as few adults will put in the study required – whereas learning a language using an alphabet, especially the same alphabet as the one everyone already knows (Latin), demands no work in that area.

    k_over_hbarc at yahoo dot com

  10. Chris Partridge said,

    July 7, 2019 @ 3:39 am

    Myopia has always been a problem in Asia. In The Glass Bathyscaphe the authors say that spectacles were crucial in the rise of Europe, because the onset of long sight in middle age rendered scholars unable to read and effectively blind, whereas in China myopic scholars could simply bring documents closer and still read. Spectacles levelled the playing field.

  11. Vanya said,

    July 7, 2019 @ 3:57 am

    Reading in general seems to cause myopia, regardless of character set. Children who learn to read English from a very young age also tend to wear glasses. The Anglo-American stereotype of the myopic bookworm exists for a reason. It is probably not so much the shapes of the characters themselves that cause myopia as the constant drilling, which means Chinese children have to spend more time physically looking at pages than children in other environments.

  12. Philip Taylor said,

    July 7, 2019 @ 6:27 am

    Vanya — "Children who learn to read English from a very young age also tend to wear glasses". Can you support your hypothesis by reference to published data, and does "English" play any significant rôle in this hypothesis or would you be willing to accept that it could equally well read "Children who learn to read from a very young age tend to wear glasses" without affecting its accuracy one way or the other ?

  13. Alex said,

    July 7, 2019 @ 7:54 am

    Unfortunately for the Chinese here, they also spend probably even more time writing the same words 20 times or more each than reading the first few years. So unlike their western counterpart Chinese here spend an even greater proportion of the time focusing on short reading / writing distances. Moreover penmanship and stroke order is at extreme anal retentive levels when young. So that one needs to focus the eyes even more.

  14. Andrew Usher said,

    July 7, 2019 @ 11:36 am

    Of course it is the writing system, not the language written, that is capable of making the difference. Surely no one could be ignorant of that. And yes, age must make a difference, in that the eyes are much more capable of changing at younger ages, and become more fixed in adulthood.

    For example, the mediaeval scholars referred to by Chris Partridge likely didn't read much in childhood, and so generally did not develope myopia, thus needing glasses to read in old age. In contrast, the Chinese started at a young age even then (I assume), as the nature of their writing system almost requires, and therefore already had the problem.

    This is all generalisation of course, and obviously I don't think you can determine someone's eyesight solely from their history of reading, etc., but it seems no one can really deny the correlation.

  15. Steve Bacher said,

    July 7, 2019 @ 4:09 pm

    Andrew Usher said "I've always considered the Chinese writing system … to be ridiculous. The positive that I see is that it prevents Chinese from being a serious rival to English as global language."

    I used to wonder how China could flourish with such a difficult writing system, until it occurred to me there is a distinct advantage to a writing system being essentially independent of the phonological content of the words being spelled. Most writing systems either are compelled to conform to changes in pronunciation over time or, more likely, ignore them, resulting in countless spelling exceptions to be learned individually.

    Is it a coincidence that arguably the two most challenging languages to learn to write and spell properly are English and Chinese, and those are the languages of the two most powerful economies on the planet? May I suggest that the mental training required to become proficient in either writing system is a factor in the brainpower that has strengthened both societies.

  16. John Rohsenow said,

    July 7, 2019 @ 4:39 pm

    A quick Google search for Chinese eye exercises and myopia turned up
    quite a few references. The most recent one that caught my eyes (sic) was:
    "Chinese Eye Exercises and Myopia Development in School Age …"
    by MT Kang – ‎Jun 22, 2016 – "Chinese eye exercises have been implemented in China as an intervention for controlling children's myopia for over 50 years…"

  17. Keith said,

    July 8, 2019 @ 3:31 am

    Research into myopia in ethnic Chinese living in Australia compared to those living in Singapore, carried out by Australia's Brien Holden Vision Institute suggests that the myopia is either caused or aggravated by lack of exposure to sunlight.

    Further research in China seems to confirm this.

  18. Alex said,

    July 8, 2019 @ 8:59 pm

    @Steve Bacher

    Id like to understand flourish and which era. If you are speaking about the modern era its because of the west and western technology. If you are talking about ancient times I would beg to differ if one considers the common man.

    With such a large population its astounding what the illiteracy rates were pre modern times. The script prevented the tapping of such a large pool of people

  19. John Rohsenow said,

    July 8, 2019 @ 11:33 pm

    Re: Chinese characters preventing Chinese from becoming a global language like English, as Andrew Usher wrote above:
    "…I've always considered the Chinese writing system (and their continued adherence to it despite knowledge of the alphabetic principle) to be ridiculous. The positive that I see is that it prevents Chinese from being a serious rival to English as global language,…"
    It has been suggested that Chinese characters (and the long, demanding time and effort to master them) was for centuries a way
    for the ruling classes in China to protect their own power (pace: the false promise that any ordinary (male) cowherd who could somehow master them, and the "Latinate" classics written therein),could in theory join their ranks by dint of hard study, etc. The baihua vernacularization movement of the 1920s and the literacy campaigns and character simplification schemes of the 1950s were touted as ways of simplifying (sic) this process and making education more available to the "masses" of workers, peasants, and soldiers, etc., and to a limited extent have in fact given a larger segment of the population some of the basic literacy necessary for living in the "modern' industrialized world.
    (I will leave it to Professor Mair to speculate as to why the early enthusiasm for switching to romanized Hanyu Pinyin was cut short
    in the 1950s/60s, and what the results might have been if it had been supported and allowed to continue.)
    BUT, can it be argued that the continued use of the Chinese character writing system also has the "advantage" for the CCP of preventing "foreigners" from culturally invading and 'infecting" China just as the old Mandarins used it to protect themselves from the peasant "masses" in the old days? Does the CCP really WANT (written) Chinese to be a
    "global language"?

  20. Alex said,

    July 9, 2019 @ 3:52 am

    @John Rohsenow

    Id imagine one world leader in the time period you asked about said to another aligned world leader, best not to switch from Chinese characters.

    I was watching a show on Pamphleteers during the american revolution and French

    During times of political unrest, such as the French Revolution, pamphleteers were highly active in attempting to shape public opinion. Before the advent of telecommunications, those with access to a printing press and a supply of paper often used pamphlets to widely disseminate their ideas.

    I think a high illiteracy rate is useful for control.

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