It's been 3.5 weeks since my LASIK was done and I have a slight pain in my left eye. My vision is good, so what is wrong?

Most likely, you are experiencing some residual dryness, which is very common during the first 3 months. Try using moisturizing drops and especially take omega-3 fish oil pills.

If your eye hurts you should see the surgeon.It could be mild inflammation or it could be dryness or a reaction to the drops you are taking.See your surgeon. If the surface is dry consider unfrozen autologous serum eye drops.