The severity of nearsightedness is often categorized like this: Mild myopia: -0.25 to -3.00 D. Moderate myopia: -3.25 to -5.00 D or -6.00 D. High myopia: greater than -5.00 D or -6.00 D.

What is considered severe nearsightedness?

Doctors generally define high myopia as nearsightedness of -6 diopters or higher, according to the American Association for Pediatric Ophthalmology & Strabismus. The Association also notes that high myopia often occurs in people with very long eyes, and typically appears during early childhood.

What is a bad nearsighted prescription?

A number between +/-2.25 to +/- 5.00 indicates moderate nearsightedness or farsightedness. A number greater than +/- 5.00 indicates severe nearsightedness or farsightedness.