April 2015 Technicians

The Vision Therapy Opportunity, Part Four

A recent report from Canada thoroughly examined the efficacy of vision therapy and found an apparent research war over its use.

April 2015 Eyes/Optics

The Vision Therapy Opportunity, Part Three

A successful vision therapy practice has many proven techniques and interesting tools (called orthoptics) at their disposal.

August 2014 Lenses

Converting Prism Into an Order

The Opticians Handbook received this question about a prism Rx for a patient experiencing vertigo:
"I recently got a prescription where the doctor asked for 1.5 degrees of prism base down at axis 255 right and 1.5 degree base down in the left at axis 255. What should I order? The doctor told me to order 1.1 base down with 0.50 Base Out right and 1.1 Base Down with 0.50 Base In."

February 2014 Lenses

Slab-off, Reverse Slab-off and Bi-centric Grinding

The most common way of correcting vertical imbalance is to induce a vertical prismatic effect in the lower half of one lens. This type of correction is referred to as bi-centric grinding, or slab-off.