Short Answer
Complete Explanation
The term “Sphere PL” is found on many optical prescriptions and denotes that the spherical component of the lens power is plano, meaning it has a value of zero diopters. This notation is used when the eye does not require any spherical correction for the specified viewing distance, but the prescription may still contain other elements such as cylinder or axis for astigmatism.
- Definition:
“PL” stands for plano, indicating a spherical power of 0.00 D. - Notation in prescriptions:
It replaces a numeric sphere value (e.g., –1.25, +2.00) and is written as “SPH PL” or simply “PL”. - Clinical relevance:
Placing “PL” informs the lab that the lens should have no spherical curvature, though other corrections (cylinder, addition) may still be applied.
Common Misconceptions
PL means the glasses are free of any correction.
PL only refers to the spherical component; cylinders, additions, or multifocal designs may still be present.
A prescription with PL is unsuitable for vision improvement.
For patients with no spherical error, PL accurately reflects their visual needs and can be combined with other necessary corrections.
FAQ
Why would a prescription show PL instead of a numeric sphere value?
When an eye has no measurable spherical error, the optometrist records PL to indicate zero diopter power, avoiding unnecessary numbers and simplifying lens manufacturing.
Can glasses with a Sphere PL still correct astigmatism?
Yes. The cylinder and axis values can still be present on the prescription, allowing the lens to correct astigmatism even though the spherical component is plano.
Is a plano lens the same as a clear, non‑prescription lens?
A plano lens has no spherical power, but it may still include other corrections (cylinder, addition). A completely non‑prescription lens is plano with no additional optical modifications.
Leave a Reply