Did he poke his actual eyeball, the side near his eye, his eye lid?
What did he poke it with? A pencil? A toy? His finger?
Sounds like some simple broken capillaries, which looks way worse than it is and takes forever to clear but but is painless and clears itself.
HOWEVER, if he's crying bloody tears, THAT warrants an immediate trip to the ER.
Hope he feels better soon.