Eye surgery and lower the risk of infection. These precautions include the use of antiseptics, such as povidone-iodine, and sterile drapes, gowns and gloves. Although the terms laser eye surgery and refractive surgery are commonly used as if they were interchangeable, this is not the case. Lasers may be used to treat nonrefractive conditions (e.g. to seal a retinal tear). Laser eye surgery or laser corneal surgery is a medical procedure that uses a laser to reshape the surface of the eye. This is done to correct myopia (short-sightedness), hypermetropia (long sightedness) and astigmatism (uneven curvature of the eye's surface). It is
Low-g condition zero gravity in the cockpit. To produce 0"g", the aircraft has to follow a ballistic flight path, which is essentially an upside down parabola. This is the only method to simulate zero gravity for humans on earth. In helicopters In contrast, low-g conditions can be disastrous for helicopters. In such a situation their rotors may flap beyond normal limits. The excessive flapping can cause the root of the blades to exceed the limit of their hinges and this condition, known as mast bumping, can cause the separation of the blades from the hub or for the mast to shear, and