Usually called prescription or Rx eyeglasses, prescribed glasses refer to all forms of spectacles that are used for vision correction. Currently there are a very huge number of individuals who have to rely on these devices on a part-time or full-time basis. The reason for the naming of prescription eyewear is that these devices should be prescribed by an eye doctor. According to the U.S. laws, prescription medical devices are not allowed to be sold without a valid prescription. Rx eyewear is strictly under this regulation. Of course, there is the opposite point called non-prescription or Plano eyewear. Regular sunglasses and protective glasses belong to the latter group. Most people know that nearsighted and farsighted patients are target user of Rx eyeglasses. But conditions like astigmatism and presbyopia are usually beyond their consideration. To be exactly, there are mainly four visual problems that require the use of prescription eyewear, namely myopia, hyperopia, astigmatism and presbyopia.

Since prescribed glasses are a medical device involving a patient’s eye health, the Federal Trade Commission in the United States requires that only an eyewear prescriber can prescribe an eyeglass prescription. Exactly, only eye doctors including optometrists and ophthalmologists have this permission. Another common role named optician only has the right to dispense, fit or adjust prescription eyeglasses. In addition, each patient has the right to ask the doctor for a copy of his or her prescription at the conclusion of an eye exam. From another perspective, the prescriber should give such a copy immediately following the exam. With a valid prescription, it is feasible to get Rx glasses from other local and online sources.

During a comprehensive eye exam, there are a couple of eye tests that may be carried out. Most of them are really necessary if the patient wants to get an exact pair of prescribed glasses. Using a projected eye chart, visual acuity test will be conducted to measure the sharpness of the patient’s vision. There are usually letters of different sizes and directions to be recognized. Color blindness test will usually be taken to rule out color blindness. Some other common tests include visual field test, cover test and retinoscopy.

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