FOCIMETRY TRANSPOSITION OF SINGLE VISION LENSES

What measurements are taken during Focimetry?

• Sphere, Cylinder, Axis

• Astigmatism

• Refraction

• Diameter

What types of lens a focimeter is measuring when a clear and blur lines image appear perpendicular to one another?

• Spherical lens

• Cylinder lens

• Bifocal lens

• Sphero-cylinder lens

Below are the sources of error during focimetry procedures, EXCEPT

• Quality of the lens

• Refractive index of the lens

• Position of the lens vertex

• Eyepiece focusing

Transpose the lens power: -3.25/+2.50 X 10

• -5.75/-2.50 X 10

• -0.75/-2.50 X 10

• -0.75/-2.50 X 100

• -5.75/-2.50 X 100

Transpose the lens power: -5.75/+1.25 X 140

• -4.50/-1.25 X 50

• -4.50/-1.25 X 140

• -7.00/-1.25 X 50

• -7.00/-1.25 X 140