Myopia (near-sightedness) setting in in one's forties? Umm... Not commonly.
More like presbyopia, age related loss of focus/accommodation ability for near work, reading and the like, typically noticed first in one's 40s reading small print in dim light, and generally thought to be related to loss of crystalline lens elasticity.
There's also hyperopia aka farsightedness. Presbyopia is often called farsightedness as well, tho presbyopia is a special term for the age related loss of lens flexibility and thus near focus.
I'm highly myoptic (-11-ish diopters, too much so for good lasik results) with astigmatism (irregular or toric curvature of the cornea or lens, thing American football shaped). Hard (gas-permeable) contacts correct more accurately for the astigmatism and give me a much wider field of view without the peripheral distortion of glasses at the required corrective values. I'm also in my mid-40s and need reading glasses to reduce the contact correction (calibrated for distance vision) by a couple diopters (so to -9-ish, still highly myoptic), thus have personal experience with astigmatic myopia from early childhood, and presbyopia for a half decade or so. Thus my personal knowledge of the subject.