by Jamie Bartlett February 08, 2021 2 min read

If you have a strong prescription, you’re in the right place.

Using this handy guide, avoid the dreaded lens-bulk by choosing the right lenses.

Better still, your eyes will look their natural size instead of being magnified smaller or bigger than they actually are.

No bug eyes for you!

 

What are double aspheric lenses?

 

Double aspheric lenses use irregular curvature on both their front and rear surfaces to make them thinner in profile, lighter in weight and aesthetically flatter. These lenses are popular for strong prescriptions to reduce thickness at their centres or edges.

 

For ease, here’s a handy breakdown of each lens profile;

  • Spheric lenses use a singular curvature on their front and rear surfaces
  • Aspheric lenses use an irregular curvature on just their front surface
  • Double aspheric lenses use irregular curvature on their front and rear surfaces

This design makes double aspheric lenses flatter, thinner and sleeker in your frame.

See the illustration below.

 

Illustration of a spherical, aspherical and double aspherical spectacle lens profile

 

What prescription type do double aspheric lenses benefit most?

Double aspheric lenses benefit strong prescriptions of more than +6.00 or - 6.00 dioptres in your sphere and/or your cyl.

  • If you’re strongly farsighted (+) double aspheric lenses will reduce lens-bulk in the centres of your lenses due to their convex profile.
  • If you’re strongly nearsighted (-) double aspheric lenses will reduce lens-bulk at the outer edges of your lenses due to their concave profile.

See the illustration below.

 

Illustration comparison of spheric and double aspheric spectacle lenses

 

Are aspheric lenses better?

Aspheric or double aspheric lenses have the advantage of being thinner, flatter and lighter weight than traditional spheric equivalents. This makes them easier to wear in your glasses frame with improved aesthetics due to their sleeker appearance.

 

Why are high index lenses so expensive?

High index lenses are more efficient at refracting (bending) light, therefore require denser, more costly materials to manufacture. Furthermore, they require finer tolerances of accuracy which adds to their higher production costs.

For a guide to high index lenses, check out my other blog here.

 

How much do double aspheric lenses cost?

In 2021, 1.67 index, CR39 double aspheric lenses cost approximately £100 including anti-scratch and anti-glare coatings.

For a personal quotation to suit your prescription and lifestyle, please get in touch.

 

  

Key takeaways

Double aspheric lenses are;

  • less distorted at their edges
  • able to provide a larger field of view
  • irregularly curved on their front and rear surfaces
  • usually made in high indexes such as 1.67 or 1.76
  • approximately 30-40% more expensive than single aspheric equivalents
  • thinner, flatter and lighter weight than spheric or single aspheric equivalents
  • required to have anti-glare and anti-scratch coatings
  • able to be tinted as sun lenses

 

As you can tell, there are a lot of options to choose from, so feel free to get in touch about your ideal set of lenses.

Hopefully you found this article useful.

Thanks for stopping by.

 

Jamie Bartlett
Jamie Bartlett

Co-founder of Banton Frameworks.



Also in Eye care

6 benefits of anti glare glasses
6 benefits of anti glare glasses

by Jamie Bartlett July 21, 2021 4 min read

Anti glare glasses helps to increase light transmission, reduce glare and gives people a better view of your eyes. Here's 6 benefits of this worthy lens coating.
Spherical vs aspherical lenses
Spherical vs aspherical lenses

by Jamie Bartlett January 29, 2021 4 min read

Strong prescription? A guide spherical vs aspherical lenses for flatter, lighter, sleeker looking lenses. Ideal for reducing lens-bulk.
Do I need high index lenses?
Do I need high index lenses?

by Jamie Bartlett January 27, 2021 5 min read

A helpful guide so you can decide if you should get high index lenses. Using your prescription, let’s see which lens thickness is best for you.