Is severe myopia due to dominant genes? If so, how the heck did the ancestor survive??

If thick glasses run in families, that is, a grandparent had them, the father has them, a daughter has them, her child has them... is that because the thick glasses are dominant rather than recessive? I've just been wondering about this, bc I've got really bad eyesight and now that I've had a baby, I'm afraid that he will end up like me and the rest of my unfortunately bad-sighted family, rather than my husband whose family are all perfect 20/20's. And, anyhow, how the heck did that ancestor of mine survive not being killed by wild animals out there? Sheesh.... Thoughts?

Genetics isn't quite as simple as that, there's a sort of cumulative effect.

Think of teeth. You can have two parents with straight teeth, but one of them passes on the gene for large teeth, and one passes on the gene for a small jaw, there's a good chance the child's teeth will be overcrowded and therefore crooked.

Myopia is caused by either eyes that are too long front to back, or corneas that are too steep. If a child was to inherit both, they'd be more myopic than either parent.

Your eyes grow the way their genetics says they will. It's not close work that causes myopia. I have been a "bookworm" since childhood and I am farsighted, not nearsighted. I suppose I should blame my farsightedness on all that bird-watching I did {huge theatrical wink}

he probably couldn't see well enough to leave the cave lol :)

Yes, it can be hereditary. It's because your eyeball is longer than average. It's often associated with high intelligence. You have a greater risk of retinal problems, so make sure you see your Eye MD regularly. ~Jennifer (certified ophthalmic associate)

It appears to be able to skip generations. I have this problem and so does my older daughter. However, in my family, a great-grandfather was the only other person known to have had it.

It is genetic, but, in most cases not a single gene.

Your myopic ancestor would have stayed in camp to cook, sew, make tools, gather herbs, apply medicine and other tasks where good near vision is an advantage.

As Judy B said, they would have hung around the camp or village, and probably got it on with lonely wives and widows while the other men were out getting killed in battle or eaten by wild animals.

And, just possibly, if you myopia didn't take off until school age, it may not have developed at all or as severely in societies without written languages. As much as some eye professionals like to deny it, there is definitely some relation between near work and myopia.