Can I have surgery to even out the height of my nipples? (photos)

Based on your description, it sounds like you are interested in areola reduction to improve areola symmetry.  This operation is certainly possible. Make sure you educate yourself about the potential downsides associated with areolar reduction surgery including the potential for spreading of the areola, abnormal scarring, areola asymmetry, and re-spreading of the areola. Also, your breast implants seemed to be sitting somewhat low on your chest wall. You may wish to discuss the use of capsulorraphy techniques to improve breast implant positioning as well.
I hope this, and the attached link, helps.  You will find a separate page, on the same website, dedicated to correction of breast implant displacement problems.

Adjusting nipple height upwards is possible, but the opposite is not so easy.  Your left side is quite high which may be partially because of the contracture you mentioned.  A capsulorraphy with raising the inframammary crease and a slightly smaller implant may get you a more normal position on the left. You should discuss all of the options with your treating surgeon, and agree to a plan before proceding.