Anisometropia can produce various symptoms, including headaches, burning, pulling, tearing, pain, nausea, fatigue, photophobia, spatial distortion, reading difficulties and double vision. In addition to the treatment options suggested by Dr. Hagan, it's sometimes possible to make isokonic glasses (by manipulating such factors as the base curve of the lenses) which will make your vision with both eyes much more comfortable. There's more information about this in the "About Aniseikonia" section at www.opticaldiagnostics.com.
Monovision may or may not be possible for you depending on the refractive error in each eye (e.g., definitely not possible if both eyes are farsighted.) Even if contact lens wear works for you now, it may not be comfortable in ten or twenty years. In your place, I'd seriously consider laser vision correction or an IOL exchange.
There are no comlications of leaving yourself with 3 diopters difference in the refractive error between eyes. In fact some people deliberately choose this to get monovision.
You have lots of opinions. Adjust to monovision. See if you can wear glasses with the 3 diopter differnce (most can't but some can adjust) wear contact lens, have lasik on the more myopic eye last choice and most expensive and risky is IOL exchange.
JCH III MD