6 ms·

I assumed outdoor time helps because your eyes spend time focusing at a greater distance. Going outside, but only to use a phone/ereader/book is likely not effe

I assumed outdoor time helps because your eyes spend time focusing at a greater distance. Going outside, but only to use a phone/ereader/book is likely not effective.

abeppu 2y ago
I think this assumption, though perhaps reasonable, is incorrect, for at least two reasons: - There are animal model studies which vary environment brightness and show a causal relationship between darker environments and myopia. The animals in the darker experimental groups aren't reading etc, and the animals in the brighter experimental groups aren't in larger cages. - There are studies on myopia that varied indoor lighting brightness and showed brighter lighting later/decreased myopia onset. Classroom sizes (or distances from desk to blackboard, etc) did not change. These studies also found a bunch of other variables were important including longer sleep time, and less screen time. https://onlinelibrary.wiley.com/doi/abs/10.1111/opo.12207 https://onlinelibrary.wiley.com/doi/abs/10.1111/opo.12207
- robwwilliams 2y ago
  It is well established that much “near work” during childhood (and even adults) contributes to myopia. Some populations are particularly vulnerable. Myopia also has a reasonable strong genetic component in humans and mice. Classic example of gene-by-environmental interaction. Here is a recent reference and meta-analysis: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9820324/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9820324/
  - Wowfunhappy 2y ago
    Did they control for the fact that people who spend more time e.g. reading likely also spend more time indoors?
  - euroderf 2y ago
    So much for the health benefits of building model kits and collecting stamps and coins.
- setopt 2y ago
  I remember seeing a study which showed exposure to UV appears to prevent myopia as well, which is another relevant factor outdoors.
- nextaccountic 2y ago
  Maybe a darker environment makes it harder to see distant things, and the benefit of a brighter environment is to enable focusing on distant objects, which is presumably possible even for the poor souls confined to a small cage?
  - RoyalHenOil 2y ago
    From what I have gathered, the leading hypothesis is that bright light induces dopamine production, and dopamine regulates the development of the eye. When these dopamine levels are too low, the eyeball elongates and becomes myopic.
deleted 2y ago
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thsksbd 2y ago
Thats been tested and its not it. The leading hypotheses a few years back is that the outdoors is very bright. Brightness levels that cannot be easily reached indoors. surely when we squint from bright light we are straining the eye. The idea, then, is that our development expects some amount of eye strain growing up.

I assumed outdoor time helps because your eyes spend time focusing at a greater distance. Going outside, but only to use a phone/ereader/book is likely not effective.

abeppu 2y ago

I think this assumption, though perhaps reasonable, is incorrect, for at least two reasons: - There are animal model studies which vary environment brightness and show a causal relationship between darker environments and myopia. The animals in the darker experimental groups aren't reading etc, and the animals in the brighter experimental groups aren't in larger cages. - There are studies on myopia that varied indoor lighting brightness and showed brighter lighting later/decreased myopia onset. Classroom sizes (or distances from desk to blackboard, etc) did not change. These studies also found a bunch of other variables were important including longer sleep time, and less screen time. https://onlinelibrary.wiley.com/doi/abs/10.1111/opo.12207 https://onlinelibrary.wiley.com/doi/abs/10.1111/opo.12207

robwwilliams 2y ago
It is well established that much “near work” during childhood (and even adults) contributes to myopia. Some populations are particularly vulnerable. Myopia also has a reasonable strong genetic component in humans and mice. Classic example of gene-by-environmental interaction. Here is a recent reference and meta-analysis: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9820324/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9820324/
- Wowfunhappy 2y ago
  Did they control for the fact that people who spend more time e.g. reading likely also spend more time indoors?
- euroderf 2y ago
  So much for the health benefits of building model kits and collecting stamps and coins.
setopt 2y ago
I remember seeing a study which showed exposure to UV appears to prevent myopia as well, which is another relevant factor outdoors.
nextaccountic 2y ago
Maybe a darker environment makes it harder to see distant things, and the benefit of a brighter environment is to enable focusing on distant objects, which is presumably possible even for the poor souls confined to a small cage?
- RoyalHenOil 2y ago
  From what I have gathered, the leading hypothesis is that bright light induces dopamine production, and dopamine regulates the development of the eye. When these dopamine levels are too low, the eyeball elongates and becomes myopic.

deleted 2y ago

[deleted]

thsksbd 2y ago

Thats been tested and its not it. The leading hypotheses a few years back is that the outdoors is very bright. Brightness levels that cannot be easily reached indoors. surely when we squint from bright light we are straining the eye. The idea, then, is that our development expects some amount of eye strain growing up.