The Conjunctivitis Curse

• Incantation: Unknown. The spell is typically referred to by its name.
• Pronunciation: Not applicable.
• Wand Movement: Unknown.
• Light: Unknown.
• Effect: Causes the victim's eyes to swell, become painfully irritated, and crust over, effectively blinding them. It is particularly effective against creatures whose primary defense is thick hide but have vulnerable eyes.
• Type: Curse

The Conjunctivitis Curse is a powerful offensive spell known for targeting the eyes. Its use is documented in several key instances during Harry Potter's fourth year at Hogwarts.

• During the Triwizard Tournament, Sirius Black advised Harry Potter via a fire-call to use the Conjunctivitis Curse against his dragon in the First Task. Sirius reasoned that a dragon's hide is magically resistant, but its eyes are a significant weak point.
• Viktor Krum, the Durmstrang Institute champion, successfully used this curse against his dragon, a Chinese Fireball, during the First Task. The curse blinded the creature, but in its pain and confusion, the dragon thrashed about and smashed half of its real eggs, causing Krum to lose points from the judges.
• Following the First Task, Madame Olympe Maxime, the headmistress of Beauxbatons Academy of Magic, accused Rubeus Hagrid of having used the Conjunctivitis Curse on the giants she encountered during her travels. She noted their eyes were in a poor state, but Hagrid corrected her, stating that the giants were simply killing each other off.

The level of difficulty for learning this curse is not explicitly stated, but its use by an accomplished wizard like Viktor Krum in a high-stakes competition suggests it is not trivial magic. It is considered a strategic and effective spell in a duel or when facing a creature with armored skin. There is no mention in the novels of a specific counter-spell or remedy for the Conjunctivitis Curse.

The name of the curse is derived directly from the Muggle medical term conjunctivitis, an inflammation or infection of the conjunctiva, which is the outer membrane of the eyeball. The condition is commonly known as “pinkeye” and its symptoms—redness, swelling, irritation, and discharge that can crust the eyelids shut—are mirrored in the magical effects of the curse.

• In the film adaptation of Harry Potter and the Goblet of Fire, Viktor Krum is shown casting a spell that strikes his dragon in the eye, but it is a simple flash of white light and is not explicitly identified as the Conjunctivitis Curse (film).
• In the Harry Potter and the Goblet of Fire video game, the Conjunctivitis Curse is a learnable spell. When cast, it shoots a red orb that temporarily blinds enemies, causing them to stop attacking (video game).