Far-sightedness also surgical treatments for far-sightedness: The term "hyperopia" comes from Greek ὑπέρ "hyper" "over" and ὤψ "ōps" "sight" ( ὠπός "ōpos"). Far-sightedness Far-sightedness, also known as hyperopia, is a condition of the eye in which light is focused behind, instead of on, the retina. This results in close objects appearing blurry, while far objects may appear normal. As the condition worsens, objects at all distances may be blurry. Other symptoms may include headaches and eye strain. People may also experience accommodative dysfunction, binocular dysfunction, amblyopia, and strabismus. The cause is an imperfection of the eyes. Often it occurs when the
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