Do Self Sharp Eyes and Thorns stack?

The chance doesn't stack, but the damage does.

The damage doesn't stack, thorns' +250% damage overrides the critical damage bonus from decent sharp eyes.

I thought regular Sharp eyes and Thorns stacked. I'm hearing that it does and that is doesn't. Which is it? -_-

They don't stack, the bonus effect you get is based on the greater effect, and the lower effect is ignored. Both icons stay because this is different depending on the class. For example, a hero would get +15% critical chance from SE and +35% chance from thorns, so with both icons up, only thorns takes effect for the critical chance bonus. However, the hero gets +140% critical damage from SE and +125% from thorns, so SE would override thorns for critical damage. A night lord gets +25% critical damage from thorns, but both the +140% critical damage and the +15% critical rate (as opposed to the +0% from thorns) override thorns, so there's no difference for night lords between having both thorns and SE and having just SE alone.