Totally distortion free lens created - Cameron Optometry | Cameron Optometry
Totally distortion free lens created

Totally distortion free lens created

Posted on 25th August 2012

It’s actually even better than the title suggests as boffins at Harvard have created a ultrathin lens that focusses light without creating any image distortion of any kind at all.

Without going into too much of the detail, lenses focus light but altering the direction and speed of light rays passing through the material. The amount of material a light ray passes through and the curvature of the 2 surfaces of the lens affect the direction light. Varying the thickness and curvature of lenses in different parts of the lens bend rays differently, focussing them or spreading them out as required.

Sort of.

All this bending of light rays causes lots of aberrations which are the names of unwanted optical distortions. Some of these you will have heard of eg defocus (such as in long and short sight) and astigmatism; but there are lots of others you probably won’t have eg coma, Petzval field curvature and so on. All these aberrations degrade the quality of the final image. We design your glasses lenses with special combinations of thickness and curvature to minimise these aberrations but you can eliminate them entirely.

If you are wearing glasses, look out through the edge rather than the centre of your lens at something white like your ceiling. You might see some coloured fringes, look through the other edge and you might see the fringes are now a different colour. This is a type of aberration called ‘chromatic aberration’.

If you’re quaffing a glass of vino, hold up the empty glass to something square behind it like a picture frame. The frame is all distorted and mishapen, this is an aberration called ‘distortion’.

This new Harvard lens has only one surface and is effectively 2 dimensional (60 nanometres thick) and not very like a lens as you would think of it. It uses tiny little V shaped ‘antennas’ made of a layer of gold on a silicone wafer. The little Vs  alter the speed of light waves instantly and they don’t require passage through a material to change direction. Altering the size and position of these ‘V’s across the surface alters the lens properties.

It’s quite obvious how a such a thin lens would be helpful in any optical system (including glasses) from a physical point of view, but the lack of aberrations is also very exciting. Super vision lenses are within our grasp!


Related Posts

Lesley and Heather celebrate a quarter century at Cameron Optometry

21st March 2019

This year marks 25 years with the practice for Lesley Kerr and Heather Grandon. The loyal and dependable duo have been at the heart of the practice for a quarter century, a period when the practice ha...

Read more

Welcome to Hemp Eyewear, designed and made in Edinburgh

27th February 2019

We are delighted to welcome Hemp Eyewear to the Frame Room this month. Proudly unconventional: the materials, the process, the design and the look. This is such an exciting brand on so many levels.  ...

Read more

Cosmetic lenses created for our patients (and for Hollywood blockbusters)

19th February 2019

Heather Muir and Heather Grandon headed south to Hemel Hempstead to Cantor & Nissel, the company we use to manufacturer cosmetic lenses for our patients. We have used the company for many years, c...

Read more

Gillian Bruce awarded medal as part of masters

12th February 2019

In June last year, we shared the news that our clinical lead optometrist, Gillian Bruce, had passed her Masters of Science (MSc) degree in Primary Care Ophthalmology with distinction. As if that wasn...

Read more