To understand Femto LASIK, you have to understand how vision problems develop and how refractive surgery helps. Refractive errors occur when the eye has trouble bending and focusing light. Types of refractive errors include: • Myopia: Trouble seeing far away, sometimes called nearsightedness. This condition occurs when your cornea has a steeper shape, so refractive surgery reduces the curvature of the cornea to correct it. • Hyperopia: Trouble seeing things that are close, sometimes called farsightedness. In this condition, the cornea is too flat, and refractive surgery is used to increase the curvature of the cornea. • Astigmatism: Imperfections in the shape of the cornea. This condition is caused by irregular curving of the cornea, and surgery can be used to reshape the irregular areas. • Presbyopia: Loss of elasticity in the eye due to aging. This is a condition that occurs with age, and happens when the lens inside the eye becomes more stiff and loses flexibility. While refractive surgery can help correct this problem in some cases, it can also prevent you from being a candidate for refractive surgery. Not all of these problems can be corrected by refractive surgery. Refractive surgery only works to correct problems that can be resolved by reshaping the cornea. When refractive surgeries are used to correct these problems, a cut is made on the surface of the eye, and a laser is used to reshape the cornea. To be a candidate for Femto LASIK you must meet the following criteria: • 18 and older: LASIK surgery of any type is only approved for use in adult patients. • Stable vision: You cannot have LASIK surgery if you have had a change in your glasses or contact lens prescription over the past year, take medications that may change your vision, or have hormonal fluctuations that can affect your vision, such as breastfeeding or diabetes. • Good wound healing: You must not have any conditions or take any medications that may prevent proper healing. • Thin cornea: People with particularly thin corneas may be at increased risk of blindness with a LASIK procedure. • Previous refractory surgeries: You may be prevented from having Femto or other types of LASIK surgery if you have had previous refractory surgeries or procedures.