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A safety shower is a unit designed to wash an individual's head and body which has come into contact with hazardous chemicals. Large volumes of water are used and a user may need to take off any clothing that has been contaminated with hazardous chemicals. Safety showers cannot be used for flushing an individual's eyes, due to the high pressure ...
The US Food and Drug Administration (FDA) defines soft contact lenses as: made of soft, flexible plastics that allow oxygen to pass through to the cornea. Soft contact lenses may be easier to adjust to and are more comfortable than rigid gas permeable lenses. Newer soft lens materials include silicone-hydrogels to provide more oxygen to your ...
Contact lenses. to correct refractive errors of the eye; a little invasive. Phoropter. used in refraction testing. Tonometers. used to determine the intraoccular pressure (IOP) - useful in glaucoma; video link for various types of tonometers. Speculum: to keep the eyes open during any operation. Universal eye speculum.
In the most familiar acuity test, a Snellen chart is placed at a standard distance: 6 metres. At this distance, the symbols on the line representing "normal" acuity subtend an angle of five minutes of arc, and the thickness of the lines and of the spaces between the lines subtends one minute of arc. This line, designated 6/6 (or 20/20), is the ...
A corrective lens is a transmissive optical device that is worn on the eye to improve visual perception. The most common use is to treat refractive errors: myopia, hypermetropia, astigmatism, and presbyopia. Glasses or "spectacles" are worn on the face a short distance in front of the eye. Contact lenses are worn directly on the surface of the eye.
An optical system with astigmatism is one where rays that propagate in two perpendicular planes have different foci. If an optical system with astigmatism is used to form an image of a cross, the vertical and horizontal lines will be in sharp focus at two different distances. The term comes from the Greek α- ( a-) meaning "without" and ...
If you're not planning to peel your fruit and vegetables, he suggests soaking the produce in a solution of salt, a solution of baking soda, or a solution of vinegar. " [This] will help to remove ...
Cleaning station. A reef manta ray at a cleaning station, maintaining a near stationary position atop a coral patch for several minutes while being cleaned. A rockmover wrasse being cleaned by Hawaiian cleaner wrasses on a reef in Hawaii. Some manini and a filefish wait their turn. A cleaning station is a location where aquatic life congregate ...