Does an ocellus provide any directional information for an organism?

Question

An Ocellus is a simple eye in many invertebrates. Everywhere I research, it says that these eyes provide no information about the direction light is coming from. But I've tested this with larval brine shrimp (which supposedly only have ocelli) and they do seem to be able to orient themselves towards the light!

I'M STUMPED, HELP!

Answer 1

How many ocelli do they have? It might be like stereo hearing: one ear just tells you that there's a sound, but with two ears you can tell where it's coming from. If they have more than one ocelli, then the light is bound to be brighter on one than the other, and they will swim in that direction.