Refractive errors occur when light cannot refract or bend properly once it hits your eye because of the shape of your cornea or lens. As a result of this, it affects your ability to see clearly. If you have refractive errors, you may have blurry or distorted vision. LASIK and PRK use excimer and femtosecond lasers to improve your vision and correct refractive errors. The combination of these highly precise lasers corrects your refractive errors and, most importantly, improves your vision beyond what glasses and contact lenses were able to achieve on their own. Laser vision correction procedures like LASIK and PRK are permanent procedures, although they cannot treat age-related eye conditions like presbyopia or cataracts. They only reshape the cornea to correct refractive errors.