If it was evident that they couldn't see (blindness was very evident) they might be exposed (abandoned and left to die). The extent of how often exposure actually happened, and what its actual intentions were, is debated though, but it is something that pops up often in common myth (Moses, Romulus, etc).

But then you have to consider what we might actually use glasses for today. Not everyone is near or totally blind, most people just need them for things like reading road signs while driving, or reading books. But, in antiquity these things might not have been as necessary (especially driving). So a lot of these people would have lived fairly normal lives.

And once you lived past a certain age, you were expected to live a life into old age, so teeth would fall out, eyes would weaken, and other parts of the body stopped working as well just as they do today. But you would stay as part of the family, live with them, and be taken care of.

As for things to help people read, certain crystals, and glass, can magnify things (hence a magnifying glass) and these things were known and used for reading and other purposes since antiquity.

Couching cataracts appears to be as old as civilization, and is recorded in cultures in both the Greco-Roman and Indian ancient civilizations. Experts in this technique could apply orbital pressure and dislodge a clouded lens into the posterior chamber, thus restoring a modicum of vision. Jesus pulled off this maneuver in Mark 8: 22-26.

Unless you were extremely blind, before the industrial age it wasn't all that important. You don't need to see all that great to plow a furrow or swing a scythe or to watch for stray animals, etc. Most people didn't read very much, if at all. If you couldn't see well you wouldn't be apprenticed into a trade where it mattered if you weren't a farmer, and most people were farmers.

>I wonder often what people with bad vision did before glasses were readily available.

Before the invention of glasses, people with bad vision had limited options for correcting their eyesight. Here are some historical methods that were used:

• Squinting: Some people with mild to moderate myopia (near-sightedness) could compensate for their blurred distance vision by squinting, which temporarily improves the focus of the eye.
• Using Magnifying Glasses: Magnifying glasses have been around since the 13th century, and they were sometimes used as a crude form of corrective lenses by people with presbyopia (age-related farsightedness). They could also be used for specific tasks, such as reading small print.
• Improvised Lenses: In ancient Rome, the philosopher Seneca reportedly used a glass globe filled with water to magnify text. Later on, in the Middle Ages, people would sometimes use convex or concave gems or crystals to create makeshift lenses.
• Seeking Help from Others: People with poor eyesight may have relied on others to read and write for them or to guide them around. This could include family members, servants, or professional scribes.