Ok I get we all look at small letters and images on screens and paper these days. Is this why in the last 150 years or so millions and millions of humans need spectacles? Is it because we are meant to be looking at things from a distance rather than nearby so our eyes haven’t caught up?
In: Biology
Many people who need glasses have relatively mild prescriptions. If they were born 150 years ago they would have managed just fine because their minor deficiency in vision would not have affected their life in any meaningful way. In this day and age, society is built around a presumption of literacy, which includes being able to read signs which means accurate distance vision that people would not have needed in the past, as well as reading large amounts of small print which would not have been expected from the majority 150 years ago. Also do not underestimate the impact of cars/driving – it is much more important to be able to accurately identify objects at a distance when you are approaching them at 50+mph and require much more stopping distance than a horse and cart.
We are actively testing people for their vision. Its relatively inexpensive and affordable for the masses.
Historically there was either no test or nothing to be done, or corrective lenses were expensive and extemely hard to acquire. You had to be very wealthy to even have the option of correction to consider. If its not even an option to consider, you just deal with it and probably don’t even really think about it much. Your eyesight was what it was.
We are primates. We evolved to pick coloured fruits out of trees and tubers out of the ground – we need close up vision – hence people are nearsighted.
We also typically didn’t breed into our old age – reading glasses become required around age 40, and therefore the need for reading glasses is not influenced by evolution. Evolution rewards traits that lead to increased breeding – anything that happens after breeding age is largely irrelevant to evolution.
You don’t need a very good eyesight to survive in an agricultural society. Yes, it’s good to have good eyesight when sewing (and it’s one of the most common complaints we have of bad eyesight from pre-industrial times) but in general only the worst level of vision impairment will cause difficulties when working the land or hunting.
If it had been 500 years ago I wouldn’t have needed glasses, but I’ve become increasingly unable to read fine print or quickly read cluttered signs etc. That’s a handicap today, but I’d manage just fine without my glasses if I had to navigate a forest, forage, harvest a field etc.
We didn’t need to see as accurately before the industrial revolution.
When do most people put glasses on.
When they’re reading.
When they’re in low light.
And when they’re driving.
These were activities that don’t typically come up for a feudal surf or a hunter-gatherer.
Most people with glasses can see well enough without them to survive in a group of people in nature. You don’t need perfect 20/20 vision to find berries. And as long as you can contribute to the tribe, people will help you out. Those with particularly bad eyes were probably eliminated, although there is evidence that tribes frequently cared for those that could not care for themselves.
Also, you really only need to get to reproductive age for a trait to be carried forward, and most people still have relatively good eyes by age 20.
Humans are unable to live alone in the wild for prolonged periods of time. A hunter-gatherer tribe can do fine if half of its members have poor vision for objects at a long distance as long as the other half have quite good eyesight.
There is also a mechanistical explanation that late 20th century/early 21th century society puts kids indoor for too long and that not having indirect sunlight into the eyes make the orbit not stop growing, so that myopia is much more common than in the past decades.
Most people with glasses could live perfectly fine with them. They’re often a luxury to see well, but their not really a requirement to live
People are stuck inside all day staring a screens, rather than being outside using their eyes properly.b
Until 150 years ago, 90+ % of humans worked on growing or raising or preparing food. A little problem with the eyesight just wasn’t a big deal. Before 1800, the average person could not read (other than recognize simple signs)
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