OD is right eye,: OS is left eye. The first #s. sphere, are negative, meaning she is nearsighted. The second #s (cylinder) is the amount of astigmatism that is present. Since astigmatism means the eye is focusing light at an angle, astigmatism comes with a rotation axis. The cylinder is rotated to this axis so that the light can be focused straight on.
Answered 11/5/2016
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