Refractive surgery is a technique in continuous evolution which no ophthalmologist should overlook. It is well known that there are many different types of laser devices available for photoablative surgery (PRK-LASIK) as a treatment for refractive errors. However, the results obtained with the different Excimer laser delivery systems when treating equal refraction amounts are inconsistent. These final results depend largely on the inherent constitutional features of each laser device. The aim of this paper is to analyze the homogeneity achieved by four different Excimer laser technologies.