Practice lab

Practice Lensometer.

Read a simulated target, compare the principal meridians, and record common single-vision prescriptions—one clear step at a time.

How this simulation works

  1. 1. Read the first focus. It gives the sphere starting point.
  2. 2. Compare the second focus. The difference tells you the cylinder power.
  3. 3. Use the dial. Record the aligned cylinder axis, then check your reasoning.

Scenario 1 of 5

Session score: 0

Plus sphere
Simulated lensometer view
Exam-practice view
Focus+2.00
090270180000
First focus
+2.00 D

Your read

Which single-vision prescription matches this focused mire?