need some advice regarding eyesight.........

[Expatriot]

I've been nearsighted all my life(I'm 68). I have always been able to read and "pick bones
from fish" without glasses.

Awesome! But irrelevant.

The reason bifocals exist is because myopia does not, and cannot, prevent presbyopia.

[nocar]

Well, my understanding is that, yes, myopia is caused by the eyeball being elongated, which makes the focal point of the light entering the eye is not fall the retina, even when the lens is not compressed at all. A young myopic person will be able to see things even closer to the eye (while compressing the lens) than a nonmyopic young person.

Of course there are myopia of different degrees. Some myopics are not myopic to the degree that reading will be comfortable without glasses at an older age, but can not see clearly at distances, and bifocals will be needed. Some will be able to read, but then see distances more blurred.

For my own part, I have one eye that is myopic to the extent that the focal point is too close to the eye for reading, so I usually use a correction glass for reading. Yet when I really need to have close look, I take the glasses off and put the object closer instead of using a magnifying glass (I am 66). My other eye is more normal.