One of the most common questions asked by those looking to purchase a magnifying glass is: which is better – acrylic or glass? The answer of course, like so many things in life, is that better is subjective, and it really depends on the needs of the user.
Before discussing the pros and cons of lens materials, it can be helpful to understand how a magnifier works in the first place. Why exactly does a magnifying lens cause small objects to look bigger than they really are?
Every magnifying glass consists of a clear, convex-shaped lens that curves or bulges outward at the center, and thins toward the edges. This lens, most often acrylic or glass, is usually fitted into a frame or handle to make it easier to read the fine print in your novel, examine the inscriptions or engravings on a coin or stamp, or work with the tiny stitches on your current needlepoint project. With a wide range of styles and magnifications to choose from, the uses for this tool that conveniently enlarges whatever you need to see are practically endless.
Basically speaking, it’s the light rays reflecting off an object and entering your eyes that allow you to see it. But when you use a magnifying glass to view that same object, the convex lens causes the reflected light rays to bend in toward each other. This happens because light slows down when it moves through a material like glass or acrylic, and the light moving through the thicker center of the lens takes longer to come out the other side than the light moving through the thinner edges.
When these ‘faster’ light rays pass through the edges of the magnifying lens first, the ‘slower’ rays passing through the center effectively ‘drag’ them back, and cause them to bend inwards. It’s this bending effect that makes the object you’re looking at appear much larger than it is, because when the light rays bend, they also become wider before finally reaching your eyes.
The Glory of Glass
Glass magnifying lenses are widely known for providing an extremely clear and distinct magnified image. Because of its density and other inherent properties, glass makes it easy for a very large amount of light to pass through a lens, and so it tends to provide superior optical qualities. It’s also very difficult to scratch a glass lens, making glass magnifiers quite durable.
The biggest problem with glass is that it’s fairly heavy. This can be a major consideration when it comes to a tool like a handheld magnifier; especially for the elderly, or for anyone who needs to make use of a magnifying glass for an extended period of time. In comparison, acrylic magnifying lenses are extremely lightweight, weighing only about one half of what a glass lens does.
Glass magnifiers do, in fact, have a slight magnification advantage over their acrylic counterparts, but they’re usually much more expensive to produce. For the average home hobbyist, glass lenses may not be worth the trade-off they often demand in terms of extra weight and cost.
The Age of Acrylic
Although glass was the original material used in magnifying lenses, its popularity has declined in recent years, and the vast majority of magnifiers sold in the United States today are made with acrylic lenses.
The reason most people prefer acrylic magnifiers is that they’re less expensive, they’re lighter and easier to handle, and the lenses don’t break easily or shatter like glass can. Even better, today’s acrylic magnifying lenses are scratch-resistant, and are specially designed to offer outstanding, distortion-free clarity. Acrylic is also highly resistant to impact and warping, and to the damaging effects of most pollutants and household cleaning solutions.
For all of these reasons, optical acrylic has become the industry standard. But one of the best things about it may be the fact that it allows manufacturers to set a smaller auxiliary lens area, with a higher magnification, into a larger magnifying glass. This means you get to enjoy the benefits of two different magnifications, in one handheld or hands-free magnifying glass.