How did knights who required glasses to see survive on the battlefield?

Question

Googling this has been less than helpful on the history factor, and a quick look at HEMA rules and regulations says it's easier to use fencing masks instead, which isn't what I'm asking. (This was mildly helpful however, considering that from what I'd found, fencers tend to get prescription sport goggles or differently shaped glasses to better fit within the confines of their mask. But it doesn't answer my particular question.)

Did they have their helmets built with the lenses in mind? (Sounds impractical to me considering that if the glass shatters, it's going directly into their eyeballs.) Did they wear their glasses under the helmets? Did they go into battle without their glasses entirely?

Answer 1

They Didn't Wear Glasses and They were Probably Fine

TL/DR: They didn't wear glasses and all but the blindest of knights were at no more a disadvantage than a guy who was slightly shorter or weaker or slower than average.

As mentioned previously the kinds of glasses available to a medieval aristocrat were essentially impossible to use on a battlefield. But that's not a huge hindrance. A knight's ability too see clearly would not have a tremendously bad effect on his combat capability until you get in the range of near-blindness. You must consider the ranges at which the average knight was fighting. My own vision is atrocious, in the 20/400 range. Anything outside of about 20cm gets fuzzy, and I have difficulty identifying individuals at distances greater than 3 meters unless they're especially tall/short/weird hair color or the only person of a specific race in the room. 20/400 is "legally blind" without corrective lenses. But I can (and have) done ARMA-style fights without corrective lenses. I can still see motion at 3 meters, even slight movements. and I can also perceive objects like, say, a spear or a sword moving at that range. Even from 20ish meters away I can still identify things like "that's a person" and "that person is moving towards/away/sideways as about X speed" and can roughly distinguish the size of a weapon they're carrying. (I can tell if something a spear or a sword, but not really a spear or a halberd for instance) What does that mean for a knight with a similar impairment?

Honestly not a whole lot. Certainly a GENERAL might have problems, as he would not be able to easily identify troop formations or banners at a distance. But your average knight was a close-combat specialist fighting either on foot or mounted. On foot he's coming within a few feet of his opponent, where his vision is "good enough" to allow him to fight with confidence, especially against an armored opponent where subtleties like facial cues don't matter and fights often ended in grappling. Against mounted opponents he'd be at a slight disadvantage, but if his reflexes were good enough he could still get his lance's final aimpoint on target. As he's part of a larger formation somebody else will be able to point him at the enemy. Unlike the movies battles didn't devolve in wild mixed-in melees so as long as he stayed "pointed" the right direction so he didn't go running up to foes he thought were friends until he was 3 meters away he'd be ok!

At the end of the day it certainly is a bit more challenging to fight without good vision than with my contacts in. But I wouldn't rate it much more difficult than fighting a guy who has slightly longer reach or is slightly stronger or any of the other minor advantages that nature bestows on people. A knight isn't trying to see a thin flitting rapier, and catching arrows on your shield is a matter of luck and good positioning rather than seeing the arrow coming. A knight is trying to see fairly large objects at fairly close range, and at that point even the just-barely-legally-blind can do ok!

Answer 2

According to Wikipedia glasses were invented in 1268 by Roger Bacon. About a century later, the first wearable glasses appear on a painting by Thomasso da Modena in 1352.

Glasses were rudimentary at best, and very expensive to make. The only people who wore glasses were wealthy scholars, because of technical limitations: those glasses were only good enough (barely) for reading. Glasses of this period were only capable of correcting presbyopia (not being able read, common for elderly people). If you accept the distortions, and didn't mind wearing or holding something very uncomfortable for extended periods. A scholar or merchant used glasses in a sedentary environment. Wearing those kind of glasses in any other environment was not practical. Least of all on a battlefield.

That's where your problem lies: a knight didn't need reading glasses, supposing they could read. Many of them couldn't. They needed to cope with myopia, or short-sightedness. That's the opposite of what glasses at the time could assist with.

The technology to create wearable glasses in a helmet or on the battlefield simply didn't exist. Glasses that help with short-sightedness weren't invented during medieval times, but long afterwards. Wearable glasses as we use to day appeared around 1727.

Answer 3

I haven't studied this at all. But common sense would lead someone to one of two conclusions. If your vision was enough of a problem that you had difficulty carrying out your knightly duties, either: a. You didn't become a knight in the first place b. You died quickly in battle

I suppose you might get lucky, become a knight, and never get called to battle. But that strikes me as extraordinary luck...

Answer 4

In addition to the other posts, I would just like to add that helmets would probably produce a minor pinhole effect which would slightly reduce some optical abnormalties.

Answer 5

I guess it would have depended on the exact time and place in the medieval era, Medieval Europe was vast geographically and temporally, covering an area of 10,180,000 square kilometres and spanning a period of a thousand years. It is entirely possible that in the latter third of the middle ages, at least a few knights would have worn glasses (I'm referring to the 14th and 15th centuries when spectacles became more practical). Knights were by and large nobles, thus would have been able to afford glasses.

Answer 6

It is indeed possible that a few knights did have glasses, especially during the latter half of the medieval period. Knights were often aristocrats, meaning they could afford glasses if they needed them (after all, it was quite pricey to equip a knight with armor, swords, horses and other paraphernalia). It's plausible that medieval rivet spectacles would have fit inside the helmet, as the glasses were relatively tiny.

On the other hand, refractive errors such as nearsightedness and farsightedness were usually seen as minor inconveniences, as with the exception of scribes and the like, very few people would have needed their vision to be crystal clear. If they could see just clearly enough to do their jobs, that's really the only eyesight thing that mattered back then.

Answer 7

Well, one helmet belonging to King Henry the 8th appears to have a pair of glasses mounted on it. Though this helmet was a jousting helmet rather than one that was ever worn in battle.