Prescribed Prism California State Society for Opticians January

Prescribed Prism California State Society for Opticians January 12, 2017

Splitting Prescribed Prism Compounding or split prism in the vertical meridian must have opposite bases direction. BU and BD – Opposite Bases This rule applies to compounding or split prism. Example: OD -1. 00 1Δ BU OS -1. 50 1Δ BD

Splitting Prescribed Prism Compounding or split prism in the horizontal meridian must have same bases direction. BO & BO – Same Bases BI & BI – Same Bases This rule applies to compounding or split prism. Example: OD +1. 25 2Δ BO OS +1. 25 2Δ BO

Practice Splitting Prescribed Prism Split Prism Answers OD: -2. 75 -0. 25 x 173 OS: -1. 75 -0. 50 x 165 OD: +1. 00 OS: +1. 50 4 BD 5 BI OD: -3. 00 -0. 75 x 086 6 BO OS: -2. 75 -0. 50 x 135 OD: +2. 50 -1. 50 x 079 OS: +2. 00 -0. 75 x 135 3 BU OD: -1. 50 -0. 50 x 080 OS: -1. 00 – 0. 75 x 145 4 BO OD: -0. 75 -0. 50 x 090 OS: -1. 00 -0. 25 x 180 6 BI For answers to the above contact the California State Society for Opticians at email: California. Society. Opticians@gmail. com

Identify if the Prescribed Prism was split correctly Was the prism split correctly? OD: -1. 50 OS: -1. 00 Answers 2 BI 2 BU 2 BO 2 BU OD: +1. 00 3 BI OS: +1. 00 3 BI OD: -0. 75 -. 50 x 145 4 BU OS: -0. 50 -. 50 x 079 4 BU OD: +2. 00 -0. 50 x 135 3 BI OS: +2. 50 -0. 75 x 079 3 BO OD: -1. 50 -0. 75 x 080 3. 5 BI 3 BU OS: -1. 00 -0. 50 x 065 3. 5 BI 3 BU OD: +1. 00 -0. 25 x 063 2 BO 2 BU OS: +1. 50 -0. 75 x 145 2 BI 2 BD For answers to the above contact the California State Society for Opticians at email: California. Society. Opticians@gmail. com

The reasons why the doctor prescribes prisms as follows: Base Out (BO) prism in both eyes may be used to compensate to relieve esotropia/phoria Base In (BI) prism in both eyes may be used to compensate to relieve exotropi/phoria Remember these notes – reasons for problems of prisms. Excessive Base : Esotropia: A marked deviation of the eye inward Esophoria: A tendency for the eye to deviate in Exotropia: A marked deviation of the eye outward Exophoria: A tendency for the eye to deviate out