Know About Prescription Glasses And How To Read The Prescription

If you have recently been to a clinic for an eye examination, you must have received a prescription that is too hard to read. No, we are not indicating that you need to wear glasses or so, but it is worth time to spend on understanding what the doctors are indicating. Prescription glasses are the last thing that one would want but knowing what the doctors prescribe and understanding the real problem behind it is necessary. So, if you fancy the optometrist jargon or even understand what the doctors mean when they write OD, OS, SPH, or CYL, then this article is for you. Today, we will unmask the various facets of a prescription starting from what the numbers mean and the abbreviated remarks to the science of glasses.

What Do The Numbers Mean And How Does It Work.?

The numbers here refer to the type of lens that is required for your eyes. The numbers depend on various factors and we will reveal that to you in a few minutes of reading. However, it is very important that you understand the basics of an eye before we delve into the features of prescription glasses. The problems faced by any individual can be either due to myopia (near-sightedness) or hypermetropia (far-sightedness).

Myopia- In this,  a person suffers from reading characters or alphabets which are at a distance of more than 5 meters. Therefore, it is called near-sightedness. It indicates that the person can read at a closer distance but as the distance increases, the ability to read fades. However, the person can read characters that are placed near the eyes.

Hypermetropia- It is also known as far-sightedness and in this, the individual can read the characters which are placed at a distance but faces difficulty in reading characters that are near to the eyes.

If an individual is suffering from any of these problems, then the doctor will prescribe prescription glasses or rectification glasses, which also commonly know as a number. The number of glasses is decided by the intensity of the blurred vision.  Usually, myopic people wear glasses with negative power whereas, individuals with hypermetropia require glasses with positive power. The numbers on the column OD, OS, SPH, and CYL refers to the power of the lens required for correction.

Unfolding Prescription Glasses Nomenclature.

As we speak of the prescription glasses, you must have seen different columns on the prescription labeled OD, OS, SPH, and CYL.

OD  - Oculus Dexter ( right eye)

OS - Oculus Sinister (left eye)

OU - oculus uterque (both eyes).

Howsoever, the terminologies have been changed now a day and the modern prescriptions do not use these terms. Instead, you will find the right eye and left eye written on the prescription.

SPH-  It is the acronym for sphere which directs to the power of the lenses in diopters. Diopter is the measurement unit of distance that needs to be corrected using a corrective lens in the prescription glasses. If the numbers appear in the minus sign (-), you are near-sighted, and when positive (+), you are farsighted.

CYL - Cylindrical refers to the amount of lens power for astigmatism. If no number appears in this column, you do not require correction for astigmatism. Astigmatism is a kind of refractive error that occurs due to irregularities in the shape of an individual's cornea. This condition leads to blurred vision as the eye fails to focus the image on the retina. In most cases, the problem starts from birth but in some cases, it develops gradually in different stages of life.

With this information handy with you, it will become easy for you to understand what is meaning of different jargon used by an optometrist or eye doctor.