If you needed glasses you were probably in trouble but then back in those days people didn't live long past the age where most people start needing them.
Probably because of their healthier and less overly processed diets and no screen time.
As to no sights on dueling pistols, it helps to understand the code of honor of the era, which was quite different from what we have today. In some ways it seems odd and even foolish to us, today, but I'm sure someone from the 1780s would feel the same about our attitudes today.
Military muskets are smooth bore, and as such not very accurate. The generally don't have sights or if they do they are very rudimentary compared to rifle sights.
People today generally figure that, well since they were smoothbores there's little point putting sights on them, and that is true, but there is also more to it. British troops in the 1700s were taught to "aim" (meaning point) their muskets at the enemy formation, directed by their officers, then "turn their heads" (look away), and fire.
It was considered "ungentlemanly" to actually look at someone when you shot them. There was a practical effect, turning your head reduces the dazzle from the pan flash, but in the main it was a point of honor. Of course it was probably disobeyed as often as obeyed, but it was the rule...
Commanders aimed units individual soldiers did not aim their arms at individual enemy soldiers. The whole point was not to specifically kill the enemy with gunfire it was to break them. The usual practice was to give the enemy a volley, then another , sometimes 3, and then charge and settle the issue cold steel.
The unit that broke under fire usually lost. The point of honor was to stand there and take fire, and that attitude carried over to duelling.
The point of a duel, unlike what appearances seem to show (and popular fiction always shows) was not to kill the other guy, it was to SHAME them.
Yes, of course there were many duels where the entire duel was contrived in order to kill someone, but those were not considered honorable, if that truth came out. History doesn't record many duels where no one was killed (there are a few but you'll have to dig for them) probably because they were not "news". But there were duels (possibly many more than you'd think just reading the usual records) where "honor was satisfied" and no one was killed. Both with blades or guns.
The point was to prove your honor, or the rightness of your cause by standing there and taking the risk. If you died as a result of that, you died, but with honor, not a craven. That mattered to people in those days.
SO, not putting sights on a dueling pistol was a way of avoiding actual aiming, which was something only a pure scoundrel would do....of course you were expected to look at your opponent and point your pistol but actual precise aiming was bad form old chap....
However there were it seems, some "workarounds" to tilt the odds in one's favor. As I mentioned earlier in this thread, some years back an actual set of original period dueling pistols was shot and tested for accuracy.
They were well made, and considering smoothbore and no sights, they shot very accurately, putting all their shots in a reasonably small group at the classic 20 paces distance. Interestingly, BOTH pistols in the set consistently shot two feet to the left of point of aim at that distance. Think about the possible results if the owner knew that and his opponent did not....