Poked my eye with finger nail how long to heal?

Depends: It really depends on what was injured with the fingernail. For example, if you scratched your cornea (the shell of your eye), usually, the abrasion will heal in 1-2 days. However, if the injury is severe enough, it could lead to infections, eye pressure problems and even vision loss. You should be evaluated by an eye md.

24 hours: The eye is the fastest healing tissue and if not infected or large it should heal in 24 hours.

About 1-4 days: It depends on the size of the scratch. Uncomplicated small scratches or abrasions can heal in 24 hours. The entire corneal surface can heal in 3-4 days. If there is infection, chemical burn, or other significant disease, though, all bets are off.