Possible side effects include:

i) Retinal detachment.  Previous research has suggested that this may occur in 1% of patients any time up to 20 years after Yag Laser Capsulotomy, increasing to 4% in patients with myopia greater than 6 dioptres prior to cataract surgery.  More recent data has suggested that the increased risk only applies to patients having Yag Capsulotomy within 4 months of surgery.

ii) Pitting of the intraocular lens.  Great effort is taken during the procedure to accurately focus the lens on the posterior capsule.  If you were to move backwards during the laser, (or even rarely during routine laser surgery) the back of the intraocular lens implant could be hit by the laser.  This results in a small pit placed in the lens.  Fortunately, this is rarely associated with any visual problems and I have never heard of a patient having to have an intraocular lens exchange as a result of this problem.