lens power measurement lensometer

1. Lensometer
Presented By Asif Faraz Nasir
M.optom

2. Definition
• Meaning
• 'Lenso'=lens
• 'Metry'=measurement of

3. Types
1.Manual,and
2.Automatic.

4. Manual lensometer
A simple lensmeter
cross sectional view.
1 – Adjustable eyepiece
2 – Reticle
3 – Objective lens
4 – Keplerian telescope
5 – Lens holder
6 – Unknown lens
7 – Standard lens
8 – Illuminated target
9 – Light source
10 – Collimator
11 – Angle adjustment
lever
12 – Power drum (+20
and -20 Diopters)
13 – Prism scale knob

5. Optics and basic structure
• also called conventional or manual lensmeter and operates on the
principle of optometer
• the optical principle of optometer developed by Badal is preferred
over the non badal principle.