What Is A Slab-Off and How Do We Calculate It?

Slab-off is a prism technique used to correct vertical imbalance. We’ll try to first understand the concept and why it is needed then work through an actual calculation. Slab-off is most often used on lined multifocal lenses but can be used on progressive and even single vision lenses. Learn More: This week I do my best to help you visualize the concept of slab-off. Slab-off is a prism technique used to correct vertical imbalance. Opticians will request slab off when the patient has anisometropia. We will work through the how and then do an actual calculation. It is through optician training that opticians learn the steps involved in solving for slab-off calculations. Slab-off is most often used on lined multifocal lenses but can be used on progressive and even single vision lenses also. Opticians using slab off calculations may need to determine the power in oblique meridians and apply the concept of the optical cross in their work. Learn More: Connect with us: This video lesson is sponsored by Laramy-K Optical Laramy-K Optical is a digital uncut and coating lab unlike any other. The only exclusively uncut lab in the country; we provide our customers with independent, high-end alternatives to corporate brands. Through craftsmanship, technology, and independent, innovative vendors like Younger, IOT, A&R, and Quantum Innovations we offer our customers the Integrity portfolio of freeform lenses and coatings. Made in the USA, the Integrity brand is not a generic house-brand, but is the absolute best available, designed to give the wearer that “wow!” experience. In addition to the digital line, we still offer conventional surfacing, including glass. Maintaining traditional equipment gives our customers vastly more flexibility in their dispensing, particularly when it comes to more difficult prescriptions. Learn More: