Eyeglasses weren’t invented until the 13th century and before then people kinda just had to deal with it. They would rely a lot on those around them and stick to work that didn’t require being able to see long distances. There wasn’t anything they could do to manage their vision problems so they just lived life the best they could. Something interesting to note is that Myopia (nearsightedness) was a lot less common back then than it is today. We don’t really know why this is but some have theorized that it correlates with the rise of literacy and frequency of reading. That’s just a hypothesis though... anyway, this means that even though there were certainly people with myopia pre-13th century, it was less common and therefore there wasn’t a pressing demand to solve the problem.