Definitions of Optical Equipment Machinery The following terms are commonly used when talking about optical equipment machinery:
Phoropter: Used by ophthalmologists and other eye doctors during an eye exam, a phoropter is used to measure refractive error, or eyesight problems. It uses several different lenses to determine refractive error in the eyes, and from this information a glass lens prescription can be determined. The lenses are adjusted by the doctor while the patient is required to tell the doctor what they can see through the phoropter.
Eyeglass Prescription: Refers to the numbers determined by an eye care professional on how strong a corrective glass lens must be. An eyeglass prescription can only be written by an ophthalmologist or an optometrist. Opticians are not allowed to write eyeglass prescriptions.
Autorefractor: Similar to a phoropter, an autorefractor also measures refractive error in the eyes and is used to diagnose eyeglass prescription strength. It measures how light changes when it enters a person’s eye, which can be used to diagnose vision problems. They are smaller than phoropters.
Slit Lamp: A machine that focuses a slit of light into the eye and is used during eye exams. It is able to examine the entire eye, including the iris, sclera and corneas. It is also used to study the retina. This machine both illuminates and magnifies the eye so that the doctor can examine it properly.
Dilation: During many tests, the eyes themselves will need to be dilated with a couple of drops of liquid formula. Dilation allows for the pupils to adjust and become larger. While it is a painless process, the patient will have trouble seeing until it wears off.