What do the terms on the EyeQue Refraction Measurements (ERM) dashboard mean?

ERM Dashboard Terms
SPHERE	Indicates the lens power needed to correct for myopia or hyperopia, measured in Diopters (D).  Negative (-) numbers indicate myopia or nearsightedness, and positive (+) numbers indicate hyperopia, or farsightedness. Nearsighted means you see better up close than far away. Farsighted means you usually see better far away and may have more difficulty focusing up close.
CYLINDER	Indicates the lens power needed to correct astigmatism, measured in Diopters (D). Following US optometry standards, this will always be a negative (-) value. Astigmatism is a common condition in which your eye is curved more steeply in one way instead of being completely round. It can cause your vision to be distorted or blurry at any distance. Please note that some doctor-issued eyeglass prescriptions will have a (+) cylinder value. If your previous prescription has a (+) cylinder value, your entire prescription would need to be mathematically converted first in order to be compared to your ERMs. Please contact support for assistance.
AXIS	Orientation (in degrees) in which the cylinder correction above needs to be applied to correct for astigmatism.
PD (Pupilary Distance)	The measurement of the distance between the centers of the left and right pupils (in millimeters).
ADD	ADD (sometimes written as NV-ADD for “Near Vision Add”), the lens power that needs to be added to the sphere to correct for presbyopia, in order to bring the vision in focus for reading. If the value is +0.00, it means you currently do not need a reading vision addition. By default, this number is calculated based on your age, which is why we collect your birth year in your account profile. This value is used by eyeglass manufacturers when you order reading glasses, bifocals, or progressives.
ERM (EyeQue Refractive  Measurement)	The recommended powers of your corrective eyewear that you would need to order new glasses online. These numbers are calculated from analyzing at least three consistent tests taken on the Personal Vision Tracker or VisionCheck. These numbers can be compared to eyeglass prescriptions from your eye doctor and for personal tracking to monitor for changes over time.