Ophthalmology & Optometry/Lens

Advertisement


Question
I was wondering how lens magnifications are determined? For a lens to magnify by large factors does the lens need to be really large or does it mostly have to do with the convexity of the lens? I can only assume a handheld telescope no matter how much money is put into it will not see distances as far as the hubble telescope?

Answer
Dear James,
It is the combination of a few parameters that include , Focal length of the lens, Refractive index, Diameter , asphericity, abbe value etc that is required in a lens to make a telescope.

High convexity in small diameter causes too much of chromatic aberrations. So for a higher convex lens diameter has to be large to minimize unwanted aberrations on the lens.

Regards
Optom.Amit Sharma

Ophthalmology & Optometry

All Answers


Answers by Expert:


Ask Experts

Volunteer


Optom. Amit Sharma

Expertise

Happy to answer any question related to the field of Optometry and opticals. Specialize in Corneal, corneal-limbal and Scleral RGP (Rigid Gas Permeable ) contact lenses for keratoconus, post lasik ectasia , dry eyes, etc,

Experience

I have been in the field of Optometry since 1989 . Worked as an Optometrist at Shroff Eye Centre New Delhi (INDIA) for 4 years. Established my own Optometry clinic In 1997 and have been practicing since then.

Organizations
OPTOMETRY CLINIC FOR SCLERAL AND CORNEAL RGP LENSES, SPECTIQUE INDIA, (www.spectiqueindia.net)

Education/Credentials
M.Optom D.Opt.(AIIMS)

Awards and Honors
Optometrist of the year 2009 Award by Cooper Vision.

©2016 About.com. All rights reserved.