OBJECTIVES: LASEK is one of the current surgical technique to correct refractive errors of the eye, such as myopia, hyperopia and astigmatism. In this method, the corneal epithelial flap is lifted then replaced after laser ablation of the subepithelial cornea. The hinged flap is created by epithelial marking and exposure of the marking ethyl alcohol (20%) for 5 seconds. METHODS: LASIK (Laser in Situ Keratomileusis) is a surgical procedure to correct myopia by corneal stroma subtraction. It involves the use of a microkeratome to make a lamellar dissection of the cornea creating a flap with intact corneal epithelium. After the flap is lifted, the underlying midstroma is reshaped with an excimer laser and the flap is returned to its original position. We have detected eighteen cases where the treatment of patients that had been subjected to LASEK with polyvinyl alcohol artificial tear drops provoked eye adverse effects. Toxicogenic keratitis, partial epithelium detachment, and allergic and toxicogenic conjunctivitis were observed. These adverse effects disappeared upon discontinuing tear drops administration and reappeared after their reintroduction. We used the Naranjo et al. algorithm to confirm the cause-effect relationship. RESULTS: All cases were confirmed as definitive. CONCLUSION: We have not observed any case of eye adverse effect in patients subjected to LASIK caused by polyvinyl alcohol tear drops.