Höðr is blind in exactly one source, and it is the one everybody reads.
Snorri introduces him in Gylfaginning as blind and enormously strong, and adds that the gods would rather not have to name him — because the work of his hands will be long remembered. That characterisation, and the blindness with it, appears nowhere in the Eddic poems.
Völuspá says only that Höðr shot the famous, too-fatal branch, and that Baldr's brother was born the following night. Baldrs draumar has the seeress name Höðr as the one who will bear the glorious slayer and be Baldr's bane. Neither poem mentions blindness, neither mentions Loki guiding his hand, and neither offers a reason.
What the blindness does to the story
The difference is not cosmetic. Without it, Höðr is a god who kills his brother; with it, he is an instrument.
Snorri's version is carefully staged. The gods have made a game of throwing weapons at the invulnerable Baldr. Loki, having got the mistletoe secret out of Frigg, finds Höðr standing at the edge of the ring and asks why he is not shooting like the others. Höðr answers that he cannot see where his brother is, and that he has no weapon. Loki hands him the shaft and points him.
Every element of guilt is removed in advance — the ignorance, the disability, the manipulation, the fact that Höðr is participating in what he believes is a harmless entertainment. He is then killed for it anyway, by a one-night-old avenger.
Whether Snorri invented the blindness or inherited it cannot be settled. It is worth noting that his name is transparent: Höðr is a common noun in poetic Old Norse for battle or slaughter, and appears widely as an element in kennings and in the name Höðbroddr. A figure whose name simply means "killing" needs no motive, and the blindness may be an attempt to explain why a god called Slaughter did the one slaughter that mattered without being wicked.
Saxo's Høtherus, who is nothing like him
Gesta Danorum Book Three gives a completely different man. Høtherus is a Danish prince, foster-son of King Gevarus, an outstanding swimmer, archer and musician — a set of accomplishments incompatible with blindness, and Saxo lists them approvingly. He and Balderus are rivals for Nanna, Gevarus's daughter.
Balderus cannot be wounded by ordinary steel, so Høtherus travels to a cave beyond a region of extreme cold and obtains a particular sword and a bracelet from a satyr named Mimingus. The two fight repeatedly across several campaigns with the advantage changing hands; Balderus at one point drives Høtherus into exile, and at another is himself defeated. Høtherus finally wounds him fatally and Balderus dies three days later. Høtherus marries Nanna and rules; Bous, the avenger, kills him in battle much later.
There is no mistletoe, no blindness, no trickster, no invulnerability by universal oath, and no innocence anywhere. The Icelandic and Danish traditions share two names and an ending and nothing else. Anyone reading Snorri as the Baldr myth is reading one of two surviving versions, and the other one was written down at almost the same time.
The problem the story will not solve
Norse literature is generally comfortable with responsibility that ignores intention: a killing creates a debt, and the debt attaches to the killer. Höðr is the limiting case. He acts without knowledge, without malice, without sight, holding a weapon someone else gave him, aimed by someone else's hand — and he still incurs the full obligation. Váli is conceived that night to discharge it.
The corpus does not comment on this. There is no scene in which anyone argues Höðr's case, no compensation offered, no acknowledgement that his position differs from a murderer's. The nearest thing to a verdict comes at the very end of Völuspá, and it is startling.
The two brothers come back
After the earth rises again from the sea, after the surviving Æsir gather on Iðavöllr and find the old golden game-pieces lying in the grass, the poem says that Baldr and Höðr will come back and dwell together in the halls of the slain god, and speaks of the gods at peace.
Killer and victim return as a pair. Whatever the poem thinks happened, it does not think the two of them are on opposite sides of it. That reconciliation — placed at the very end of the world, not before it — is the closest Norse mythology comes to a statement about guilt without intent, and it is one line long.
Whether the returning-and-reconciled ending is authentically pagan or shows Christian colouring is one of the standing arguments about Völuspá; see Ragnarök and the Norse tradition overview for how much of the surviving eschatology may have been shaped in transmission.
Almost nothing after
Höðr has no cult evidence and no place-names. Modern reception is thin: he appears occasionally in fiction as the blind archer, and Wagner left him out entirely. Marvel has used the name for a minor character with no relation to the source figure. The one genuinely arresting thing about him — that Norse myth contains a defendant with a perfect defence and convicts him anyway — has never made it into a popular retelling.
Was the weapon a mistletoe dart, an arrow, or a sword?
Völuspá calls it a mistilteinn and describes it as a slender, too-fatal shaft, shot. Snorri makes it a stick or twig, thrown or shot at Loki's direction. Saxo has a special sword and no plant at all. Complicating matters, mistilteinn survives elsewhere in Norse literature as an actual sword-name — the hero Hrómundr Gripsson fights with a blade called Mistilteinn in his saga. It is therefore possible that the earliest version had a named weapon and that later tellers, reading the word as the plant, built the botanical story around it. Mistletoe does not grow in Iceland, which is at least suggestive.
Is Höðr counted among Odin's sons?
Snorri lists him as a son of Odin and brother of Baldr, and the Völuspá stanza about the avenger being "Baldr's brother" implies the same household. But Höðr is missing from several enumerations of Odin's sons, and no source names his mother — Frigg is generally assumed and never stated. The family tree draws the descent Snorri gives while marking that the poems only ever establish the brotherhood with Baldr, not the parentage.