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?

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    It's also entirely possible that myopia wasn't even a widespread problem. It's entirely possible that our indoor lives are causing myopia.
    – Nelson
    Nov 16, 2022 at 1:49
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    @Nelson This is probably true, though Aristotle seems to have noted it and also Galen. It has been hypothesized that myopic people, in ancient Greece at least, specialised in making things like fine jewellery. Nov 16, 2022 at 2:57
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    You just point your lance at the angry blob and aim for the center! Nov 16, 2022 at 3:24
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    More importantly, how did the knights update their Instagram during the battle? Surely their metal gauntlets would not work with the touchscreen.
    – Daron
    Nov 16, 2022 at 11:19
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    Try blaming reading instead of screens or indoors. nature.com/articles/s41598-018-28904-x Nov 16, 2022 at 22:12

4 Answers 4


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!

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    @Martin: I agree, I “only” have -1dpt near-sightedness but even in bad light I’d have absolutely no problem seeing a spear several meters away. Even archery could work, I have no problem distinguishing a human shape 100m away.
    – Michael
    Nov 16, 2022 at 11:40
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    Not to mention that while full-fledged glasses are rather advanced (and expensive) technology, there's another rather simple treatment for the inability to focus light properly - holes. The kind of vision holes found in a bascinet are enough to very effectively improve vision. Not a massive disadvantage when you already need full-helmet protection.
    – Luaan
    Nov 16, 2022 at 12:09
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    @Luaan there is an even better low tech solution: squinting
    – Christian
    Nov 16, 2022 at 13:28
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    @Luaan: It's called "pin-hole camera" effect - and simply squinting makes a difference. This seems like the best answer to address some misconceptions by OP re "myopia. My vision is somewhat better than Martin's, but not a whole lot. However not being able to distinguish the mortar lines in a brick wall beyond 20 feet doesn't mean I can't identify it as a brick wall. I might have difficulty distinguishing Ron Weasley from Fred/George at 10 feet - but I'll still know he's a tall red-haired male even from 80 or more feet. Nov 16, 2022 at 14:38
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    I wonder how eyesight would impact your ability to identify friend from foe. Not so sure how easy it was on medieval battlegrounds to identify which side a knight is fighting for
    – Carsten
    Nov 17, 2022 at 10:50

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.

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    @MCW "The first lenses for correcting astigmatism were designed by the British astronomer George Airy in 1825." (from wiki) Nov 15, 2022 at 15:28
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    @JamieB you're thinking of musketeers as snipers, shooting at individual enemies. That's a mistake: musket formations shot primarily at other formations. Even quite-bad eyesight can still be plenty good enough to see a formation at musket ranges. My eyesight is not great (something like 20/100), but I can still see where a person is at 100 yards, at least against a contrasting background. That's good enough to shoot in the right direction with more accuracy than the average musket provides.
    – fectin
    Nov 15, 2022 at 17:28
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    Hmm, I have a hard time reconciling the two statements "...myopia, the opposite of what glasses at the time could assist with" and "Glasses that help for hyperopia or far-sightedness weren't invented during medieval times". Which one were the glasses invented for back then?
    – ilkkachu
    Nov 15, 2022 at 20:07
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    @JamieB Even ignoring the fact that most archery was volley fire and not one person shooting at a single target, archery is arguably more about math or muscle memory than sight. I’m legally blind and I do just fine with archery provided I have accurate information about the shape of the target and the range, and I know a number of people who have even worse vision than me who are not only decent archers, but actually place well in archery competitions. It’s no different than modern artillery computing firing solutions ahead of time. Nov 16, 2022 at 1:48
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    I think you’ve confused near-sightedness and far-sightedness in your answer. A knight doesn’t have to see things closer than a meter or so clearly. Therefore for a knight being far-sighted is no problem, but being near-sighted would be.
    – Michael
    Nov 16, 2022 at 11:29

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...

  • 4
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  • What about nobility by blood? Knights were not all commoners who became knights by good deed, many were born that way Nov 18, 2022 at 9:42
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    @PierreArlaud not every noble born man became a knight. One who lacked the physical requirements could for example go into the clergy instead.
    – jwenting
    Nov 21, 2022 at 13:36

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.


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