Table of Contents
What does changing the axis on contacts do?
When the axis of the cyl changes, it simply means that the front shape of your eye has changed. A small change in this shape can often give a larger change in axis, so this is nothing to be concerned about, providing your eyes are healthy. It may even occur over what seems like a short period of time.
What does 150 axis mean in eye prescription?
The axis for both eyes falls between 150 and 180, so this prescription would correct “with-the-rule astigmatism,” (see sidebar, above) meaning the vertical meridian of each cornea is steeper than the horizontal meridians. Meridians and Rx’s.
What do the Axis numbers mean on a contact lens prescription?
Typically given in 10s, the axis figure on a contact lens prescription can be between 1 and 180. Ninety means that the cylindrical power is positioned vertically to correct your astigmatism, whereas 180 would suggest it is positioned horizontally.
What is the meaning of Axis 180 on a prescription?
This is with reference to the lens itself. With reference to the eyes, an axis of 180 (which is the same as zero) is horizontal. The meaning of the axis number on the prescription defines the direction in which the zero power axis of the lens should be oriented. With reference to the eye, picture a clock face centered on the pupil. An axis o…
How many degrees do contact lenses rotate?
Ten degrees is 1/3 of the rotation from one clock hour to the next. When a contact lens is fitting well, each blink will lift the lens and rotate it slightly. It may rotate 5 to 10 degrees or more. When the eye opens after blinking the contact drops and settles into its proper place on the cornea.
How much rotation is normal in toric contact lenses?
A soft toric contact lens with about 5° left rotation. Note the three toric lens markings on the inferior portion of the lens. It is tempting, if patients appear to be satisfied, to ignore small amounts of lens rotation.