burkphoto Loc: High Point, NC

It depends on the lens. A plastic barrel is not necessarily inferior to metal! It can be more dimensionally stable under temperature changes. Delrin and other modern plastics can be very hard, without being as brittle as their metal alternatives.

Plastic lenses? Again, it depends on many factors, especially which elements, what coatings, etc. Some are excellent and some are not.

Rely on lab tests and real world sample images to judge image quality. If you’re picky, wait until the lens has been available for a year before you buy it. That gives the manufacturer time to revise design and manufacturing to fix any issues.

leftj Loc: Texas

I'm curious. What are a couple of lenses that are all plastic and have no glass?

burkphoto Loc: High Point, NC

Eye glasses can be all plastic to keep them thin and light...

BebuLamar

The lenses for my eyeglasses cost $700 for 2 plastic single element lenses. They charge too much.

camerapapi Loc: Miami, Fl.

Perhaps I do not understand your question but as far as I know ALL lenses in the optical formula have glass. Aspheric surfaces are the only ones that have a combination of plastic and glass but that will be only one element of the lens.
If you are talking about plastic construction understand that most plastics used in lenses today come from experiments that were made during outer space trips and they have excellent quality and are lighter than metal. Plastics do not expand and retract with atmospheric conditions like metals do.
Ask any repair station about those plastic lens mounts and they will tell you it is not common to have one for repairs...except when the operator has shown negligence.

burkphoto Loc: High Point, NC

I feel your pain. I’m glad I had cataract surgery in 2008! No more expensive glasses...

leftj Loc: Texas

That was not my question.

gordone Loc: Red Deer AB Canada

People buy expensive glass optics and shudder at the term plastic lens. Then they put an expensive Lee ND grad filter in front of it and think nothing of it. The Lee ND filter is made from resin (AKA plastic).

mgoldfield

I agree wholeheartedly!

I have worn glasses since I was about six years old - over 70 years ago.

I held out for glass lenses until several years ago when I was unable to obtain them and had
to accept plastic lenses. My nearsightedness is very severe so my lenses are pretty thick.
Well I can tell you there is an observable difference between plastic and glass.
I've gotten used to it, but when I got my first pair of plastic lens glasses I could tell the difference,
and I didn't like it. The glass lenses have a crispness and clarity which the plastic lenses lack.

Every optician I've met agrees; however, most people don't notice the difference.

M. Goldfield

kymarto Loc: Portland OR and Milan Italy

As long as plastic is clear, without internal flaws, the transmissive capacity is similar to glass (there may be slight differences depending on the type of glass and plastic). Different glasses have different indices of refraction, and I assume that so do different types of plastic. As long as a given plastic has the same index of refraction as a given type of glass, it should make no difference in the optical quality of the lens with a few caveats:

First is the question of the quality of the curvature. You want an even and smooth curvature of the lens surface. It may be that glass is easier to face than plastic. But if the quality of the surface is the same the optical quality would be the same.

Second is the question of dimensional stability. You don't want a lens to lose its desired shape. Again, I am not a materials scientist so I don't know which would be better.

Third is a question of hardness (which relates to the first point) Scratch resistance is of course a major point. I'm also unclear on the question of anti-reflection coating on plastics.

Fourth would be resistance to changes that would relate to transmission. I'm guessing that some plastics would yellow or become partly opaque over time or in the presence of strong light. Again, this is a question for a materials scientist.

But given a good and stable plastic, there is no reason that a lens element made of it need be inferior to one made of glass with the same optical characteristics.

TheShoe Loc: Lacey, WA

It does not follow. I had the surgery last year and the surgeon told me that a genetic aberration in my eye made it impossible to install the "all distances" lens replacements. I still have to wear glasses for reading or other close work.

Daryl New Loc: Wellington,New Zealand

Dirtfarmer sums it up....

flashgordonbrown Loc: Silverdale, WA

Not completely true - some lenses have both acrylic elements as well as glass elements. As has been pointed out in another response, acrylic is commonly used in high quality eyeware, and has for many years in combination with glass in quality camera lenses. This from many years of camera retail sales, ending more than 25 years ago! In the interim, I have maintained close contact with the industry as a professional photographer.

CO

The hybrid aspherical lens elements are the ones that are a combination of plastic and glass. A step up from that are the molded glass aspherical lens elements. The best ones are the precision ground glass aspherical elements but they are expensive to manufacture..

mas24 Loc: Southern CA

I paid $400 for one pair of eye glasses made of plastic lenses. The Optometrist told me they were of high quality scratch resistant plastic. That price was for frame and lenses. Way overpriced, IMO. There has been much debate as to whether or not to use protection filters on your camera lenses. However, the glass on your lens is actually harder than the protective filter glass. But, I still use one anyway. The common accidental nose dive on concrete, that happens sometimes, with your camera and lens mounted on a tripod, can still cause damage to your glass lens.