I noticed a white spoy on my iris. it itches and is very red my eye also wont stop watering. is this an emergency?

Almost: I am concerned you may have a corneal ulcer and you should see an ophthalmologist at your earliest convenience.

Yes: A white spot over the iris is likely a condition affecting the cornea. With associated symptoms of redness, watering one needs to rule out infection like a corneal ulcer. Often there is pain with an ulcer, but this could be at an early stage. The white area can spread and become a scar that affects vision if not appropriately treated in early stages, so i would be seen by an eye specialist asap.

Yes : Yes this most likely is an emergency. You are likely seeing a collection of white blood cells in the cornea (the tissue in front of the iris). This can represent a corneal ulcer which is an emergency. You should see your eye care professional immediately.