Side effects encountered to varying degrees and for variable periods of time in patients following laser vision correction include tearing, light sensitivity, foreign body sensation, blurred vision, fluctuating vision, discomfort or pain, reduced quality of vision in dim light (loss of contrast sensitivity), night glare and halos, and dryness of the eyes.

Non-sight threatening difficulties which have been reported with laser vision correction include too much correction, too little correction, unpredictable healing response (regression or loss of effect), delays in healing of the epithelium (PRK), a scratch of the corneal epithelium (LASIK), a worsening of a pre-existing ocular muscle imbalance in farsighted individuals (wandering eye), dry eyes, increased light sensitivity, glare and halos at night and LASIK flap complications (incomplete flap, buttonholed flap, free flap, flap displacement, flap wrinkles, growth of surface epithelium under the flap, debris under the flap).

Potentially sight-threatening problems that have been reported include: infection, haze and scarring (PRK), corneal surface irregularity with irregular astigmatism resulting in distorted vision not correctable by glasses or contact lenses (loss of best corrected vision), inflammation under the flap (LASIK) and progressive corneal thinning (ectasia).  In severe cases a corneal transplant would be necessary to restore vision.