A Guide to Understanding Your Eye Exam

Among the most common eye problems found in teenagers to adults and kids to elderly are nearsightedness, farsightedness, and astigmatism. Typically, followed by the visual acuity test, eye testing process and questioning session eye exam in Colorado Springs and eye doctor in Colorado Springs prescribe you with required eyeglass to help performing your activities normally with corrected eyesight. You take the prescription to an optician who prepares your glass according to the specs prescribed by the ophthalmologist or optometrist.

Even though the prescription with the details of specification appears to be incomprehensive to you, however, by decoding the symbols and abbreviated terms you can effectively understand what the prescription says about your eye health condition and its weaknesses. Whether you are shortsighted or farsighted vision issue and its acuity point. The guidelines below can help you interpret your eye test report successfully.

A Guide to Understanding Your Eye Exam

What ‘OD’ and ‘OS’ Mean

The foremost factor of your prescription to understand is the meaning of OD and OS. They are acronym forms while OD stands for ‘oculus dexter’ (directs Right eye), and OS stands for ‘oculus sinister’ or left eye. Doctors are also using another term OU, which means ‘oculus uterque’ i.e., ‘both eyes’. While these are the traditional coding systems, many doctors these days used to write RE (right eye as well as LE (left eye). In the prescription, OD comes before OS since doctors involved in eye exam in Colorado Springs and eye doctor in Colorado Springs see patient’s right eye on their left as they face them.

The other abbreviations

Sphere denoted by ‘SPH’

SPH specifies the extent of lens power needed for correction of nearsighted or farsighted people. If you see (-) minus sign, this means you are shortsighted, having problem to view things far. Conversely, if it’s (+) sign, it would mean you are farsighted. You have problem to read small words of books or newspaper. I.e. nearer things.

Cylinder denoted by ‘CYL’

It indicates the extent of lens power needed for astigmatism. If nothing is mentioned here, you should understand that your astigmatism is too negligible to correct with an eyeglass.


Axis denotes the lens meridian. Axis is defined by numbering it from 1 to 180. Here, number corresponding to 90 indicates vertical meridian while number corresponding to 180 indicates horizontal meridian.

Important: Meridians of one’s eye are found by assuming a protector scale on the eye’s frontal surface.


This denotes additional magnifying power to be applied to the lower part of a multifocal lens for correction of farsightedness. The number appears with ‘+’. In general, it should be the range between +0.75 to +3.00 D for both the eyes. For rectification of shortsightedness, it should be the reverse.

Difference of Single and Multi-focal eyeglass

One’s single vision correction need indicates lens power for improvement of your farsighted problem or address nearsighted issue but not both. On the other hand multi-focus or bifocal are meant for those who need correction support for nearness, farness and intermediate range vision.

What are Visual Acuity, Eyesight, and Vision?

Whereas the largest part of people often make mistake while distinguishing Visual Acuity, Eyesight and Vision, here is the details

• Visual acuity refers to the sharpness of your visual power. This is tested with standard Snellen eye chart by eye doctors during eye exam in Colorado Springs and eye doctor in Colorado Springs. Visual acuity is measured keeping the chart static while you sit at a distance and read the alphabets on it enabling the doctor to offer you necessary correction glass.

• Eyesight typically means one’s ability to see things or ‘sense of seeing’.

• Vision can indicate either of visual acuity or of eyesight.

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