The white spot you have on your iris seems to be a Brushfield spot, I found this in Wiki:
and something more to the point here:
Q: What does a white spot on the iris mean?
Last night I felt like there was a piece of dust in my eye and I noticed redness. This morning i noticed a tiny pimple-like white spot on the surface of the iris. I do wear contact lenses. What could it be?
Best Answer - Chosen by Voters
"means you should get to your eye doctor as soon as possible. Those white spots are usually the beginnings of corneal ulcers, which can be bad if not treated properly. Usual symptoms that accompany the spots are pain, redness, tearing, sensitivity to light, and feeling like there's something in your eye.
Typically, this comes from a few sources. Patients are sleeping in lenses they're not supposed to, keeping their lenses too long, not cleaning the properly (if at all), cleaning them with non-name brand solutions, work in dirty or dusty environments, or have bad allergies. Any one, or combination, of those will cause problems with your contacts.
So, I'd make an appointment with your optometrist as soon as you can. You need some prescription medication for that and maybe new contacts as well.
I'm an optometrist"
I felt his answer was relevant to your question, since you mentioned contacts. I never had contacts, so I wouldn’t know the first thing about them.
What did your ophtha say about the white spot?