How long will it take for a hyphema (squash ball) eye injury take to heal?

5-7 days critical. This is when re-bleeding can occur, do activity must be extremely limited. After that there could be a few more weeks before things seem healed. Severe injury could even require surgery. A cataract or glaucoma could develop even years later so it is important be be checked at least yearly after such an injury.
Depends on severity. A microhyphema without blood layering may resolve in a few days. An "eight-ball" hyphema or completely filled anterior chamber may take weeks to heal and may even require surgical evacuation. Rebleeding and secondary glaucoma are common and prolong resolution of hemorrhage.