How Far Can Legolas See?

There's a famous scene in the Lord of the Rings where the elf Legolas claims to be able to count the exact number of horsemen 5 leagues away, and on top of that can tell that their leader is very tall. But even with the most perfect eyes possible, would anyone be able to see that far?

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Thanks to Nima Doroud for contributions.
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[Njald]

The answer is quite clear imho. Aragorn asks Legolas "What do you see with your Elven eyes?" This is obviously a misprint, Aragorn actually said "What do you see with your Eleven eyes?" Legolas is usings his eleven eyes to functionally create a larger lens like linked array telescopes.

[qwertyuiopazsd]

What if Legolas just made up their height to sound cool?

[bouchandre]

We all know that Legolas doesn't care about physics. He has shown us in the last Hobbit movie how he can defy gravity too.

[BosonCollider]

Clearly Legolas gets around this problems by using both his eyes as an interferometer. So he should be able to tilt his head to the side to tell the height of the riders.

That or Elves have huge anime-sized eyes. That works too.

[Nurl-esh]

Actually a dilated human pupil can get to 9mm which means that the angular size of a airy disk is 0.004º and not 0.007º. so to an object 24km away the disk only forms with objects smaller than 1.68m. Considering that they have the same cones than us they can see blue light in objects bigger than 0.0033º so he could maybe distinguish as little as 1.4 (or a tall dwarf). An average horseman height (horse height+sit man height) would be 2.44m. Finally elf iris can be bigger than humans even with normal eye size so their pupils can be even bigger and their S cones (blue light) respond to shorter light waves so maybe they can see even sharper. As long as their brains are "programmed" to adjust the light better than ours and they have a bigger density of rods and cones, it is Physically possible for Legolas to see that well.

[yunikage]

Elves are explicitly magical in LotR. They can do all sorts of shit that's physically impossible.

Their fucking bread is magical, ok?

[TheNeCafe]

I think people are missing the point of the video, I don't think the point is to scientifically analyze a fictional book character's eyesight, but instead to teach about light, waves, how we see, etc. using a character from a popular book in order to get people interested (it's similar to how math textbooks for young kids use things like candies, cute animals, etc. as examples)

[ChipeloAndCrew]

Well there goes everything I thought about Legolas

[Girl]

As Legolas I can confirm that it is magic.

[zoeredadams]

We are missing one vital piece of information: Legolas actually has massive anime eyes

[Tuchulu]

Maybe he heard them but he said "see" in order not to blow everyone's minds away

[nonaerenada]

But can he see why kids love the sweet taste of cinnamon toast crunch?

[KhailAnonymous]

They're taking the Hobbits to Eisengaurd

[GRIMGORIRONHIDEROCKS]

I've always assumed, even as a child, that since the setting takes place in alternate/fantasy universes, so are the laws of science that govern them. Legolas would have been more than capable of seeing that far with precise detail because the laws of physics are not the same laws in our universe. Also Elves (at leased in tlotr's universe) are slightly magical so his heightened senses will be further enhanced by magic.
So yeah, because (modified) Science! And because Magic!

[MithranArkanere]

Elven eyes exist in more than 3 dimensions. They seem human-sized, but they are actually like telescopes. We only see the part of the eyes that exists in our 3 dimensions.

[FacelessDeviant]

1. You assume that elven eyes work the same as human eyes. 
2. You assume that light works the same in middle earth.
3. Magic.

[Callico_]

People actually arguing that he's an Elf so OF COURSE his eyes are different... It's a book with dragons and rings that make you invisible, its all nonsense!

[SandeepRao]

He was an Elf and Immortal. And the Laws of physics of our world does not exactly match the Middle Earth's. So yea he could see in 4k resolution 24kms away :p

[KrimzunFlare]

0:51 scared the crap out of me, he looked like a Titan right before he covered himself with the paper

[Yoshieatscookies]

But he is an elf with human size eyes. It could be possible that even with the same size eyes his eyes would difract differently allowing him to see objects gurther away with less blur