Crazed Lenses and How to Avoid Them
Crazed Lenses: A Brief Introduction
If you’ve ever spent time working with pottery (and specifically, glazing it), you may be familiar with crazing. If you haven’t, we’ll summarise it for you now. When you apply a glaze to the clay vase (etc.), you run the risk of forming a network of tiny cracks all over the surface. You might see it on some antique vases, but it’s also a common occurrence somewhere far outside the realms of the potter’s studio: your glasses. Crazed lenses can crop up now and again if you have certain lens coatings; we thought it would be best to give you the lowdown on how to fix a problem like crazed lenses before it gets out of hand.
Viewing the world through crazed lenses can make your field of vision seem blurry; certainly not what you want if you’re driving, for example!
What Causes Crazing on Lenses?
Crazing is usually caused by the improper application of anti-reflective coating when eyeglasses are made in the lab. Crazing (or lens cloudiness that resembles crazing) can also be caused by:
- Cleaning your glasses with rubbing alcohol, window cleaner or another harsh household cleaner - at VisionDirect, we always send a spray bottle of non-abrasive lens cleaning fluid, specially designed to clean your lenses without harming them.
- Extreme temperature changes that can cause the AR coating (and the lenses) to rapidly expand and contract.
- Wearing glasses while doing ‘hot’ activities like grilling, tending a fire or welding.
Crazing may suddenly appear on your lenses with no obvious cause. In these cases, this crazing may be related to a manufacturing defect.
Can Transition Lenses Get Crazing?
Transitions and other brands of photochromic lenses can become crazed if they are coated with anti-reflective coating. As mentioned before, crazing on transition lenses is often caused by exposure to heat. This doesn’t mean you can’t wear them outside on hot days, but just be wary of quick temperature changes. If you jump into a pool with some glasses on that you’ve left outside in the sun, it might not end well.
How Can Heat Damage Eyeglass Lenses?
High heat can damage lenses in several ways. Excess heat causes the anti-reflective coating and the lenses to expand at different rates. This creates crazing, a web of fine cracks that appear on the lenses. Heat also can damage glasses by:
- Softening and warping plastic frames.
- Warping eyeglass lenses.
- Damaging the film on polarized sunglasses.
To mitigate the effects of heat-caused crazing, remember to never leave your glasses in a hot car, and avoid wearing your glasses in extreme heat.
How to Prevent Crazing on Eyeglasses
You can prevent crazing and surface scratching by taking proper care of your glasses. When your glasses get dirty, rinse them with lukewarm (NOT heavily soapy) water to remove dirt and debris. It’s the best way to clean your glasses right. You can also try some ‘soft’ non-corrosive detergent and a clean, lint-free cotton or microfiber towel or a lens spray made specifically for cleaning eyeglasses.
How Can I Fix Crazed Lenses?
It may be possible to remove crazing from eyeglasses by stripping the anti-reflective coating from the lenses. However, it must be noted that we do NOT offer this service at VisionDirect, and you should certainly not do it yourself.
Some eye care professionals and optical labs have access to stripping solutions that can be used for this purpose, but the results can vary based on the type of lens and coating used.
For example, it may not be possible to strip AR coating from polycarbonate or high-index lenses.
Some glasses wearers turn to DIY solutions, including vinegar and glass-etching compounds that can be purchased at craft stores. We really do not recommend this. DIY results are unreliable - it's your vision that’s at stake. Crazed lenses repair is best left to the professionals.
Is Crazing on Glasses Covered Under Warranty?
“Manufacturers' defects means flaws or defects arising from the manufacturing process and non-conformance to the manufacturer's standards set for the particular product. In the context of eyewear this usually refers to defective hinges, welding points, discoloration etc. Please note that manufacturer's defects DO NOT include design defects which are attributable to the product design rather than the manufacturing process. Manufacturer's defects also DO NOT include damage or harm arising from product misuse or accident or your own usage of the product.”
How Can You Spot Crazing?
If you suddenly notice you don’t see as well out of your relatively new glasses, crazing may be to blame. From the wearer’s point of view, you might experience a slight sensation of hazy vision. However, if you take your glasses off and have a look at the lenses close-up, you might just spot that telltale web of hairline cracks.
Lens Coatings at VisionDirect
While we usually like to answer customer FAQs in our Optical Centre, we don’t tend to have any complaints about crazed lens-related issues. Want to know why? We think it’s because we offer unique, high-quality vision solutions in the form of Arise HD Prescription Lens coatings. These lenses are custom made with a range of coatings to protect your eyes - and your lenses. They’re perfect for night driving, and suited to tough conditions. They’re an all-encompassing premium lens, which is why we love them.