What is the result of the transposition of +3.00+2.00x90?

Transposition is a process used in optics to convert a prescription from one form to another, particularly from plus cylinder form to minus cylinder form, or vice versa. The general steps involve changing the sphere and cylinder values while modifying the axis accordingly.

For the prescription +3.00 +2.00 x 90, when we transpose it, we carry out the following steps:

1. Combine the sphere and cylinder values: The plus cylinder +2.00 at axis 90 means we are adding +2.00 diopters to the sphere value at an orientation of 90 degrees. To transpose this prescription, we will add the cylinder value to the sphere value.

• The new sphere becomes +3.00 (original sphere) + (+2.00) (cylinder) = +5.00.

2. Change the sign of the cylinder: The sign of the cylinder changes from a positive value to a negative value in transposition. Therefore, +2.00 becomes -2.00.

3. Adjust the axis: When we change the cylinder's sign, we also need to adjust the axis. The original axis was 90 degrees, and when the sign changes, the axis shifts by 90