"Ah, but the Third Hallows is true Cloak of Invisibility ... I mean to say, it is not a traveling cloak imbued with a Disillusionment Charm, or carrying a Bedazzling Hex or else woven from Demiguise hair, which will hide one initially but fade with the years until it turns opaque. We are talking about a cloak that really and truly renders the wearer completely invisible ..."
-- Xenophilius Lovegood (DH21)
The Bedazzling Hex is a spell which causes the target object to temporarily blind any observer. The spell can be used to create invisibility cloaks (DH21).
References from the canon
- Xenophilius Lovegood said that a travelling cloak may be imbued with a Bedazzling Hex in order to make it function as an Invisibility Cloak (DH21).
bedazzle = temporarily blind someone with flashes of light
There may be a sly undertone of humor in Mr. Lovegood's remark about bedazzling an ordinary cloak to make it invisible. In the Muggle world, to "bedazzle" can mean to embellish clothing with rows of rhinestones or fake gems - and those certainly don't make clothing less visible!
From the Web
"Bedazzling Hex" from Harry Potter Wiki