Understanding a Spectacle Rx Flashcards
What does OS, OD, OU each stand for?
OS is Ocular Sinister which is left eye. OD is Ocular Dexter which is the right eye. OU is Ocular Uterque which is both eyes.
What are the four main parts of a spectacle Rx?
Sphere, Cylinder, Axis, and near vision Add.
What type of info does the sphere contain?
The amount of correction needed . Plus means hyperopia and minus means myopic.
What happens if no Rx is needed or if only sphere power is needed?
“Plano” or “PL” means no Rx . “DS” or “sph” means only sphere power is needed.
What are the quarter steps in diopters?
0.00,0.12,0.25,0.37,0.50,0.62,0.75,0.87
What does the cylinder section mean?
it means astigmatism. Optometrist usually use - sign which is OD and ophthalmologists uses + sign which is MD.
What does the axis section mean?
It indicates where the power of the lens is located. 0-180 degrees.
What is the reading add section?
Patients who need help with near vision. It will always be a plus number. +0.75D-+3.00D
What do presbyopic patients usually get?
They need to have bifocal correction which is written in the add section.
What is PAL?
notation for progressive lenses.
What is FT28?
Flat Top 28 mm wide.
What is TRI?
Traditional Trifocal design.
How much of a traditional trifocal add take up the bifocal add?
50% or it can be specified.
What and when is prism is prescribed for patients?
Patients for whose eyes need help working together and it’s written in diopters along with a notation of base direction.
What are base directions?
Always refers to the base of the prism. BO means Base Out. BI means Base In. BU means Base Up. BD means Base down.
