Gouge

You can temporarily blind a creature when you use Sneak Attack with a piercing weapon.

Prerequisite: Rogue, piercing weapon.

Benefit: You treat the spear as a finesse weapon. Additionally, on your turn, you can choose to gouge a creature's eyes after a successful sneak attack with a piercing weapon. The creature is allowed a Constitution saving throw to negate the effect. The DC is equal to 8 + your proficiency bonus + your Dexterity modifier. If the creature fails its saving throw, it is blinded until the end of your next turn.

Once you use this feature, you cannot use it again until you finish a short or long rest.