Why Glassblowing Safety Glasses Need Side Protection

Why Glassblowing Safety Glasses Need Side Protection

An unfortunate trend we have observed in the glassworking community is the use of ordinary glasses and sunglasses fitted with sodium flare lenses. When fitted with a suitable lens, it is possible for these eyewear to provide sufficient radiation protection when directly viewing a flame, however there are significant risks of injury associated with using frames that lack full coverage protection including perimeter and lateral side protection.

Glassworkers should consider form and function as the primary needs of protective gear, rather than style.

Problem #1 - Light Leakage

Ordinary glasses are not designed to prevent light leakage, which can occur around the perimeter of lenses, through the frame material itself (if transparent or semi-transparent) or around the bridge of the frame which may have a too "open" design. According to ANSI/ISEA Z87.1 for use in activities requiring radiation protection such as welding, the fully assembled glasses must be checked for light leaks.

In addition, for frames that include side shield protectors, the radiation transmission characteristics of the side protectors should meet or exceed those of the primary lenses.

Problem #2 - Poor Impact Resistance

A common source of eye injuries is from foreign objects which range from dust and debris up to large objects such as tools, furniture, or other materials that may be blunt or sharp.

Industrial accidents by their nature are unpredictable. Something under pressure explodes, sending things flying, a tool slips, or glass breaks.

The problem is that ordinary glasses are not designed to take a hit. A number of things can happen that can lead to injury of the eye or face. If the lens is struck by a heavy object, it can be dislodged and pushed through. Safety glasses frames are designed with an extra deep lens groove to prevent push-through of the lens. Ordinary glasses may be made from materials that deform easily under pressure, such as acetate - a type of plastic that is designed for comfort and style but has low mechanical strength. Deformation can cause a lens to become dislodged, or can cause parts of the frame to come into contact with the eye or face. Ordinary glasses sometimes have exposed sharp edges on the interior surface - most commonly with certain metal components such as spring hinges. Upon impact spring hinges can open wider than expected allowing the inside corner of the hinge to come into contact with the face or eyes. In some cases spring hinges have been known to cause severe laceration of the face requiring emergency medical care.

Safety glasses are most commonly made from high-strength plastics such as TR-90 nylon and polycarbonate. These materials are resiliant and tough - they absorb and deflect energy by allowing some flexibility, but tend to return to their original shape without permanent deformation. Most commonly safety frames use a long screw embedded directly into the plastic to anchor the temples to the frame front at the hinge, which is virtually impossible to dislodge by accident. When unexpected impacts occur when wearing an ANSI Z87 compliant safety frame your chances of a serious injury are well managed, but if wearing ordinary glasses the risks are substantial.

Problem #3 - No Side Coverage

Do you really need side coverage?  It is easy to think, you will always be looking directly at what you are doing and if anything goes wrong the lenses will protect you, because you are looking at the work area.

Unfortunately this is wrong, and an extremely dangerous line of reasoning. But why? The reason is, when the unexpected occurs, our reflexes kick in and cause us to do the worst possible thing which is to look away. And when this happens, if your glasses don't have sufficient side coverage, the risk of injury is very high.

Think of this situation - a piece of glass breaks or explodes in front of you. Without thinking you turn your head to avoid shards of glass flying into your face. Now, if you are wearing glasses with a regular "dress eyewear" style these present a relatively flat surface just in front of your eyes. Unfortunately for you, as your head rotates away from the explosion, these lenses turn from an asset into a liability. Flying debris can enter laterally through the unprotected side area, and then actually bounce off the inside of the lenses and into the eyes.

If you think this sounds unlikely, it is not - because it happened to me. Yup, even with over a decade of experience in eyewear design and full knowledge of the need to wear safety glasses, I once was in a situation where I should have been wearing appropriate glasses but wasn't when a piece of glass broke violently. A tiny shard of glass bounced off the inside of my glasses and scratched my cornea. Fortunately that was the extent of the incident but I can say with certainty that a lesson was learned!

In Conclusion: Just Say No to Aviators, "Geek" Glasses, Etc

Unfortunately many vendors selling glassworkers safety eyewear continue to provide their lenses in frames that are not safe. If you see styles like aviators, "geek glasses" and regular dress eyewear this is a red flag.

That said, not all unrated eyewear are inherently unsafe - indeed some sunglasses brands such as Oakley are known for making sports eyewear that are capable of passing the ANSI Z87.1 industrial safety standards.

You can protect yourself by reviewing the following checklist when considering a new frame:

1. Is the frame made from a high-strength plastic such as polycarbonate or TR-90? If yes, great. Do not use frames made from acetate (think: typical Warby Parker glasses) as they are unsuitable.

2. Does the frame have exposed metal spring hinges or any sharp corners on the inside surface? If yes, avoid - these could deform and cut your face during an impact event.

3. Does the frame have good protection against stray light and light leakage around the perimeter of the lens? If not, avoid - don't forget: glass torchworking exposes you to sources of optical radiation in the UV and IR bands that are not visible to your eyes.

4. Does the frame have side shield protection? If not, avoid - lateral protection is non-negotiable.

5. Are the side shield protectors clear? If yes, avoid - these have inadequate protection from stray light in the peripheral vision.

6. Is the frame and/or lens marked "Z87"? If yes it is likely that the frame is compliant with ANSI Z87.1 safety standards.

Note that for use in special purpose activities such as welding or glassblowing, basic Z87.1 compliance is not sufficient as the lenses and frame may also need to pass additional requirements such as meeting or exceeding a particular welding shade number (e.g., Shade #3, Shade #5 etc).

As always, should you have any questions or comments please get in touch! We'd love to hear from you.

Back to blog