Questions about genetics and inherited traits

I am curious about a couple of things and hoping some of you with knowledge about genes can help me.

I was talking to my mom the other day about how my 8 month old son is showing traits that definitely come from my side - his body shape, his temperament, etc. He definitely has his father’s eyes though. I mentioned this and she agreed, and she said “well hopefully he will have good eyesight then.” This is because I needed glasses at a young age while my husband has perfect vision.

Is visual impairment an inherited trait? Is it completely separate than the eye genes for color and shape? Son’s eyes are big and brown like his dad’s, (mine are blue) but does that mean he is likely to have his good vision too? Or does one have absolutely nothing to do with the other? I know there are also some reasons for poor eyesight that are not genetic, so there is no guarantee either way. Just wondering if his chances for good eyesight are better than if he had eyes that looked like mine.

I await your knowledge!

First, I’m not a doctor or a geneticist. But: I believe that the traits of eye color are probably separate from those of vision quality. Anecdotal example: I have the worst vision in the family (awful, nearsighted since early childhood), but my eyes are the same color as my father’s. He did not use glasses until he was quite elderly, and then only for reading.

My younger daughter has eyes like a hawk. Her paternal grandmother, just reaching 90 y.o. next month, also has excellent vision, just needing reading glasses in her advanced years. But they don’t share eye color.

You’ll just have to wait and see.

Eye color is controlled by a gene for pigment. IANAgenticist, but I doubt that the same gene would be controlling the size and shape of the eyeball, which is what causes most of the differences in vision you’d be asking about. (Note that the size/shape of the eyeball is a very different thing than the size/shape of the opening in your skull that your eyes look out of. When you’re talking about the shape of your son’s eyes, I’m assuming you mean the latter.)

Both are inhereted traits, but involve different genes. Also, eyesight is more affected by non genetic factors, such as ambient light while the eyes are developing. Eye color is generally not affected by environment other than extreme deficiencies.


Another anecdote to agree. I “have my father’s eyes” in the way they look, but not the way they see, if you know what I mean. He still has better than perfect vision at 57 years old. My mother and I, on the other hand, can interchange our glasses without ill effect, and have absolutely dismal eyesight (well worse than 900/20.)

My son has the same looking eyes my father and I do, and at 12 years, recently got very weak glasses to see the board at school. By his age, my eyes were already awful. His father has nearly perfect vision.

While I’ve been told that reading voraciously at a young age has nothing to do with weakening the eyes, I have to admit I wonder about that. I was the sort of kid to read all day, every day. Lots of that reading was done lying in bed, both during the day and at night. I fell asleep every single night reading a book, and was often caught after lights out with a flashlight under the covers. And the current limit to my vision is exactly at the distance I’ve always held my books when lying in bed - about 10 inches away from my nose.

My son, on the other hand, hated books and would have nothing to do with them outside of school assignments until about a year ago. About six months before he needed his first pair of glasses.

Do kids who read books wind up needing glasses… or do they read books because they can’t see well enough to play sports?

I was a voracious reader, but my best focus without glasses is NOT where I hold my books. In fact, my vision is so poor I can’t read without my glasses (well, OK, I can make out large print…) So what does that prove?

Yeah, environment has an effect, but it’s not the whole story. Neither are genes. Both contribute.