Are these really good counter examples - they all have common explanations of this sort (whether or not true idk)? We have glasses because modern society requires focusing on close objects like books and screens causing eye strain. Cars are great for modern society but pretty poor and hunting an animal in the middle of a forest, etc.
While i doubt its the only factor, diets higher in sugar than what hunter/gathers would have eaten seems plausibly linked to there being more cavities in modern times.
>We have glasses because modern society requires focusing on close objects like books and screens causing eye strain.
This doesn't make sense. This only explains why people use reading glasses or bifocals over the age of 40.
Most people needing vision correction are near-sighted (myopia), not far-sighted (hyperopia). We have glasses because we need to be able to see things and read signs at distances greater than our arm reach.
There's something else going on causing SO many people to need vision correction.
>Cars are great for modern society
As someone who lives in a walkable city with excellent public transit, I completely disagree. Cars are a disaster and a cancer on society.
>While i doubt its the only factor, diets higher in sugar than what hunter/gathers would have eaten seems plausibly linked to there being more cavities in modern times.
I think this is a big thing, though I think it's more complicated because some people eat plenty of sugar and still don't have cavities, so I think sugar affects different peoples' bacteria differently, or different people have someone acquired or evolved different bacteria that respond differently to sugars. But yeah, sugar seems to be a central issue.
I would argue it is more to do with the amount of sugars and the frequency these sugars are in contact with the teeth than anything. Sipping HFCS the entire day seems to be much more common these days..
It's amazing how much your vision improves by simply focusing at the edge of your eye resolution level. Don't squint, just focus. A month later you will be blown away.
This becomes difficult for someone whose eyes are mismatched.
Would practicing with one eye properly covered, to have low enough lux to prevent the natural feedback mechanism which causes myopia[1], seem impractical?
[1] Extended or frequent exposure to low-contrast input causes lengthening of the eye, and can be irreversible after two weeks[2]. Seems to involve eye and visual cortex, and to not occur if the eye has no connection to the visual cortex. I'm not aware of any similar mechanism to account for far-sightedness.
[2] Consequently, nightlights and other light sources which shine into a sleeping area may be counter-indicated.
While i doubt its the only factor, diets higher in sugar than what hunter/gathers would have eaten seems plausibly linked to there being more cavities in modern times.