Note that Reverse Glasses only cuts the ATK of monsters currently on the field. After playing this card, summon a monster capable of attacking multiple times to inflict a great deal of damage at once.
This card can be very useful in a "Ghostrick" deck. If you have any face-up Ghostrick monsters on your field during your turn, you can use their own effects to flip them face-down before using this card, and then simply Flip Summon them. Xyz Summon "Ghostrick Dullahan" afterwards if possible for an even more overwhelming ATK advantage, allowing you to topple nearly any monster in battle. Alternatively, Summon "Ghostrick Socuteboss" to destroy one of the weakened monsters and lock a Monster Card Zone.
If you're about to take a large amount of Battle damage from an attack(s), this card can reduce it to a more manageable level, potentially saving your Life Points from being wiped out. The same idea can apply to your monsters being targeted by an attack. You will still lose a monster, but the damage will be heavily reduced.
Throw in a "Damage Diet" to further reduce the damage you'd take, leaving you with enough to turn the Duel around in your favor.