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Eyes and dim light

steenkh

Philosopher
steenkh
Joined
Aug 22, 2002
Messages
9,192
Location
Denmark
When I was young, it used to be said that reading in dim light was damaging to the eyes. However, I think that some years ago I saw this belief classed as an urban legend, but when asked to provide proof for it, I could not find it, not even with google.

Can somebody confirm or reject that it is an urban legend?

I am strictly speaking about damage to the eyes. Head-ache does not count - I imagine that it is the brain that must strain itself to read in dim light, not the eyes. I could imagine the eyes could be damaged if they have problems focusing with too little light.
 
steenkh said:
but when asked to provide proof for it, I could not find it, not even with google...
Click to expand...

Proof your google skills are lacking

Keywords: "reading in dim light" eyesight

159 hits.

Status: myth.
 
When I was young, I simply asked my opthalmologist (that's a doctor who specializes in eyes). Of course, that's before we had the webbernet, back when we had to rely on common sense.
 
Re: Re: Eyes and dim light

Rob Lister said:
Proof your google skills are lacking

Keywords: "reading in dim light" eyesight

159 hits.

Status: myth.
Click to expand...
I seem to have a lot to learn! I cannot remember my original search criteria. Thanks a lot!

And, TeaBag420, in Denmark, if you want to see an opthalmologist, you have to make an appointment a year in advance!
 
Ok, so you don't have to fear reading in the dark.

But remember, if you cross your eyes and someone hits you on the back, they'll stick that way.
 
This myth probably came about because it's harder to hold focus with your Iris all the way open, so tracking and accomodation will be slower and less accurate.
 
But that's my favorite way to read ghost stories! They just don't have the same effect when reading them at high noon outside in a densely populated area.
 
In my country there in general we assert that reading in the dark is bad and harmful.

I would assert that

"Reading in the dark(under dim condition) causes myopia"

Logical reasoning.

1.I think, myopia is caused by bad reading habits.
Eg. putting books too close to your eyes.
Reading in the dark or under dim condition. Causes people to bring the book closer. Thus causing myopia.

"Reading in the dark" usually implies
"Reading a book with small wordings in the dark under dim lighting". And do not usually implies looking at a faraway, dimly lit, neon signboard.

Dim lighting condition makes a short sighted person more difficult to see. http://www.nyee.edu/faqlist.html?tablename=faq&key=26&print=
The natural tendency is to go nearer, and this becomes a bad habit forming.

A slightly shortsighted person who is not wearing lenses to correct will move closer to read. This accelerate his shortsightedness.
 
Jyera,

Do you have any actual evidence for your claim ?

You seem to have confused cause and effect. Holding a book close are both effects of short sightedness and reading in low light conditions. They do not need to share a common cause, neither does one cause another.

Standing in the sun makes you hot, wearing too many clothes makes you hot. There's no evidence to show that:

- Wearing too many clothes makes you stand in the sun
- Standing in the sun makes you war too many clothes
- Wearing too many clothes makes it sunny
 
The Don said:
...
You seem to have confused cause and effect. Holding a book close are both effects of short sightedness and reading in low light conditions. They do not need to share a common cause, neither does one cause another. ...
[/B]
Click to expand...
With regard to "Holding a book close". I'm suggesting that it is both one of the effects, as well as one of the causes for shortsightedness.

"Holding a book close" as an effect to shortsightedness occurs primarily when you are VERY seriously shortsighted.

When you are just mildly shortsighted, you need not hold a book closer to see better. You just isn't able to see things far clearly.

Holding a book close is mostly a bad habit.

Dim lighting condition makes a short sighted person more difficult to see. See this reference.
http://www.nyee.edu/faqlist.html?ta...q&key=26&print=

Which can be compensated to some extend by moving closer.
(But I doubt this compensation is always effective.)
Long period of closer-range-viewing causes the shortsightedness to worsen. The bad habit and the compensation starts a harmful cyclical process resulting in worsening of short sightedness.

I have no research to cite to support this cyclical effect. Just my reasoning.

But I do not expect there will be any research to prove me wrong. How to ask a group of students, to read their books 20cm away from their eyes, under dim lighting condition?
Would you do that to your young child to prove me wrong?

From a practical point of view, many parents will assert to their child and the society that "reading in the dark is bad". For the sake of managing the child's reading habit. Same for me.
 
Consider these questions also:

1. With corrected or perfect eyesight, we could read a book placed 1.5 meter away. Why don't we do so ?

2. Did the length of our human arms caused shortsightedness?

If we had 2 meters arms and can flip our books 2 meters aways would our shortsightedness problem in the society lessen? Will use of wireless computer keyboard helps?

3. Why is reading related to shortsightedness?
 
Jyera said:
...
1.I think, myopia is caused by bad reading habits.
Eg. putting books too close to your eyes.
Reading in the dark or under dim condition. Causes people to bring the book closer. Thus causing myopia.

....
Click to expand...

And what about genetics?

You do understand WHY the vision of people with myopia is fuzzy? It has to do with where the focal point lands inside the eye... and that is usually due to the size of the eyeball and the shape of the lens.

See the illustration here:
http://www.medem.com/medlb/article_detaillb.cfm?article_ID=ZZZYXB80Z9C&sub_cat=38

In my case the eyeball is too large for my lens, and the focal point is before the retina. Also, my lens is shaped more like a football than a round lens... hense I have astigmatism.

Anecdotal data to follow:

I stipulate that this is due to genetics because I could see quite well out of the eyeglasses of both my mother and my brother (my father having normal eyesight, only needing reading glasses as his ability to change focus deteriorated with age... presbyopia).

THEN... one child has also developed myopia WAY when he was only 9 years old... and way before we could ever get him to read much at all, much less in the dark.

Also, one other child has hyperopia (farsightedness), which was discovered when he was 4 years old, BEFORE he even learned to read -- or was interested in seeing things too far away (other than Barney and Thomas the Tank Engine videos).

THEN... the one child of ours that IS the consumate reader, even in the dark and at all times is the absolutely only one who so far has perfect vision (possibly taking after her maternal grandfather). She is the only one in this house who has made it through 4th grade without requiring any kind of corrective lense.

By the way, those of us with myopia have excellent closeup vision. We see up close what many folks need a magnifying glass for.

Oh... by the way... both theories to causes of myopia seem to be in play:
http://www.aoa.org/eweb/DynamicPage.aspx?site=AOAstage&WebCode=Myopia ... Though I favor the genetics theory. Also a check on http://www.ncbi.nlm.nih.gov/entrez/query.fcgi for "myopia causes (genetics or stress)" shows that there is lots of research. This includes following families in with large percentage of myopic member (oddly, the two I saw were Danish, one in Minnesota, and my mom was from a Norwegian family in Wisconsin... weird)... and evaluating children in various schools in Hong Kong.

Cool eye/dim-light/brain fact I learned while daughter was doing report on owls... Owls have excellent vision, they are sight hunters at night --- but since so much of their head and brain is devoted to sight: Owls are really very dumb. There is no such thing as a wise owl. She learned this fact by visiting the Raptor Center at the zoo: http://www.zoo.org/educate/fact_sheets/raptors/gh_owl.htm
 
Hydrogen Cynide,

Yes, I do understand the physical/technical reason why vision of people with myopia/shortsighted/nearsighted is fuzzy. http://www.prk.com/eye-surgeons/refractive_errors.html

Yes I'm aware of there is "Genetic vs Environment" debate.
I think both affect myopia. I'll pay more attention to the "Environment" factor.

1. To say "myopia is 100% due to Environment" is more likely to be right than to say "myopia is 100% due to genetic". For the simple reason that, no matter your genetic makeup, there are 101-ways to damage your eyes.

2. People who are genetically destined to have myopia, will still fight their gene to be corrected. And environment is their allies.
(lasik surgery, better reading habits, diet habit)

3. People who are genetically immuned to myopia, may be allowed to believe, that all people are genetically destined to have myopia, or not to have. But it would be socially irresponsible for them to assert PUBLICLY something like.... "Gene determines myopia, so read all your books in the Dark in Dim lightings. Abuse it !"
 
http://www.aoa.org/eweb/DynamicPage.aspx?site=AOAstage&WebCode=Myopia
"Since the eye continues to grow during childhood, nearsightedness generally develops before age 20."

Children, learns by examples from others around them.
If they are not genetically immune to myopia,
how do ask them to stop damaging habit?

Especially if the adult ...
Say - "Reading under dim lighting do not cause myopia"
Do - Read in the Dark.
and then Say - "Don't read in the dark!!!"

Reasoning with children is fine. But even adults are not always reasonable, as we often see in forum such as ours.
 
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