How add the spectacle power ?
What is Addition in optometry ?
When the patient have distance and near vision power prescription, that time we need to do addition for the near power.
Addition means the add the distance and near power of eye.
When the patient has distance power is Plano at that time we not require to addition just written the near power as patient accept.
Near power with age and work
Near power is given as randomly as patient age and the work of patient
40 - +1.00
42. +1.25
45. +1.50
47. +1.75
50. +2.00
52. +2.25
55. +2.50
How to do addition ?
It is technique or mathematically calculation it's is very easy and the fast method to write the near power.
There are basic four rules to add the distance and near power.
1. When Distance plus power add near plus power when add value and sign should be plus
Ex. +1.00+ (+2.50)= +3.50
2. When distance minus power and near minus power then add the value and sign should be minus.
Ex. -2.00+ (-1.00) = -3.00
3. When distance power is minus and near power is plus at that time value is substract and sign of big number.
Ex. -2.00 + (+1.00) = -1.00
4. When distance power is plus and near power is minus at that time value is substract and sign of big number.
Ex. +2.00 + (-1.00) = +1.00
Cylindrical power and cylindrical axis should be same as distance vision.
OPTOMETRY-SHARP VISION
Optometrist