3 ms·
It is only ability to focus that goes down so for a person without myopia only near vision is affected. This is still bad as it affects the gatherer part of hun
by fpoling 7y ago
It is only ability to focus that goes down so for a person without myopia only near vision is affected. This is still bad as it affects the gatherer part of hunter-gazerer society, but it does not imply that evolution has not tried to optimize vision for people over 40 years old. They still can spot a lion far away.
- Retric 7y agoQuite a bit breaks down with age including a massive reduction in night vision. https://www.allaboutvision.com/over60/vision-changes.htm https://www.allaboutvision.com/over60/vision-changes.htm This might not seem like a major issue to us, but would be if trying to walk around by starlight at night.
- fpoling 7y agoThat does not imply that evolution has not tried. Human ancestors had much shorter life span and even millions of years can be not enough to fully adapt the vision for a longer lifespan especially when things works good enough. Witness flatfish. We have good records for species to see that it took tenths of millions years for eyes to move 90 degrees on the head after fish ancestors decided to lay flat on the side on ocean floor. It was good enough for the fish to see with single eye most of the time and evolution had little room for improvements since any wrong move with change in vision implied no vision and death.
- Retric 7y agoEvolution has clearly been doing quite a bit. But, so much about our environment has been changing so quickly it’s more like a first pass than the deep optimization you see with say sharks. If the Bronze Age had lasted 10+ million years many things would have changed.