Viewing a single comment thread. View all comments

Cavemanb0b t1_itjxpss wrote

Reply to comment by Sensitive_Answer2446 in Is every single living cell adjacent to or “have access to” a capillary? Are there living cells not next to a blood/O2 source, and if so, how do they survive? by Friggin

I burned my cornea recently. I was amazed at how quickly it healed. Not sure how it healed so quick, but given how important vision is to our survival it makes sense that this tissue would have evolved that ability.

8

etv123 t1_itk0rvf wrote

Did that hurt as terribly as I would think?

6

HauntingSentence6359 t1_itku9mk wrote

I cut my cornea on the sharp edge of a leaf. Initially, it was very painful, but after a couple of days, the pain all but disappeared. Until the pain subsided; my eye constantly teared.

3

Cavemanb0b t1_itsya7f wrote

Yeah. Pain peaked two hours after and then diminished as it debrided, peeled, and healed.

There is this stuff called Tetracane, they put it in your eye in the emergency room. Totally worth the trip. 😉

1

69SadBoi69 t1_itlmd2a wrote

I wonder why so many people these days have bad vision despite being able to reproduce? Is it something environmental that is recent enough to not be selected out of the population?

I had to get glasses in elementary school, and presumably most of our ancestors in that situation would not have survived long in the distant past without strong social support

1

kafkasquared t1_itlty0a wrote

it’s a good question. but having good vision to the extent that we need it today (to read whiteboards, computers, books, etc.) wasn’t necessary for the majority of human evolution. sure, you may be a bit less capable at seeing that buffalo off in the distance, but it needn’t be sharp for you to see it, and as long as whomever you’re with is seeing it, you can still assist with the kill. maybe people with truly horrible vision were selected out, but in general, i don’t see why you couldn’t thrive and reproduce in primitive times with, for instance, typical near-sightedness.

3

chronoflect t1_itmo59p wrote

If I recall correctly, we are currently going through a near-sightedness epidemic that is thought to be caused by things like not spending enough time outside in bright sunlight. Basically, our eyes need environmental cues to properly finish growing, and our modern lifestyles are stunting this growth and forcing more people to develop near-sightedness that would have otherwise had normal vision.

2