How to Diagnose Myopia

Myopia, more commonly known as nearsightedness, affects about a quarter of the population and is easily corrected with contact lenses, glasses or surgery. A person with myopia can see near objects clearly but has difficulty seeing distant objects. Myopia is primarily classified into axial myopia (the eye is too long) and refractive myopia (the cornea has too much refractive power).

Instructions

• 1

  Observe the symptoms of myopia caused by compensation behavior. This is most commonly fatigue while driving, playing sports or any other activity that involves looking more than a few feet away. Other symptoms in this category include eyestrain, headaches or squinting.

• 2

  Confirm myopia with an eye examination from an ophthalmologist or optometrist. The eye specialist usually will use a retinoscope in the examination, then use a phoropter to refine the patient's prescription.

• 3

  Identify mild myopia as requiring -.75 diopters or less of correction. This is equivalent to 20/40 vision, meaning that a person with this degree of myopia sees as well at 20 feet as a person with normal vision would see at 40 feet.

• 4

  Define moderate myopia as requiring between -.75 and -1.5 diopters of correction. This corresponds to a vision between 20/40 and 20/80 and will require correction in order to receive a driver's license in most states.

• 5

  Categorize severe myopia as requiring between -1.5 and -2.5 diopters of correction. This includes patients with a visual acuity between 20/80 and 20/200. The definition of legal blindness is visual acuity worse than 20/200.