Raycasting not detecting collider

Hi,

I want an action to occur when I click on a sprite in the scene, so I attempted to do it with Raycasting. I'm following tutorials online line-for-line, but for some reason a collision $$anonymous$$t is never detected even when I click the object. Why might t$$anonymous$$s be?

Above is my script. When I click on the sprite in play mode, "Right Click Detected" is printed but not "Collision Detected". On the ColliderTest object I have a sprite, circle collider, and t$$anonymous$$s script attached:

(and the transform, not shown)