Lens-Maker's Glasses

The Lens-Maker's Glasses is a returning item in Risk of Rain 2. It increases your Critical Strike chance by 10% for every stack. Critical strikes will deal double damage calculated after items like Focus Crystal and Shaped Glass, and they are reflected by a sharper hit sound and a red tint on the damage numbers if they are enabled.

Collecting 10 Lens-Maker's Glasses' will allow you to achieve 100% critical strike chance, effectively doubling your damage output. Having more than 10 Lens-Maker's Glasses will not increase critical chance or damage any further, and have effectively no effect.