Your opponent must keep their hand revealed. Once per turn, during your opponent's Standby Phase, if they have a Spell(s) in their hand: They gain 1000 LP if they have a Spell(s) in their hand at resolution.
Rulings
Individual Card FAQs
When "The Eye of Truth" is activated in a chain you do not see your opponent's hand until "The Eye of Truth" resolves. So if "The Eye of Truth" is step 3 in a 5 step chain, steps 5 and 4 will resolve, then "The Eye of Truth" resolves and your opponent reveals his/her hand, then steps 2 and 1 resolve.
When "The Eye of Truth" is active and a card such as "Robbin' Goblin" requires that the opponent discard a card from their hand randomly, the opponent should hide and shuffle his hand, discard a random card, and then reveal their hand again.
Trap|
Continuous