The difference between flat, dust dam, close fit, and sealed safety eyewear

April 17, 2024

Safety eyewear is worn to shield the eyes from dust, dirt, flying debris, and other projectiles from cutting, hammering, crushing, and other operations that may generate particulate. The use of safety eyewear to protect from flying dust and debris is most common in heavy industry including construction, mining, manufacturing, and oil and gas worksites in Alberta. Nowadays, it is even common to see homeowners using safety eyewear for DIY projects, lawn care, and other work around the home.

Unfortunately, not all safety eyewear is created equal, and some can fall short in their protection. In windy conditions, for example, with dust being blown around, it is a common complaint that some designs of safety eyewear can allow dust into the wearer’s eyes. To prevent this, wearers must select a model of safety eyewear with the right design to ensure the appropriate level of protection.

Fortunately, today’s safety eyewear manufacturers prioritize both function and ergonomics, including fit and comfort. Choosing the right frame design to keep dust out, even in windy dust-blown conditions will help limit eye exposure to debris while providing added comfort and cushioning. This also helps to reduce unintentional self-inflicted eye injuries that may occur when the worker rubs his or her eye due to getting dust or debris in the eye and possibly resulting in a scratched cornea.

Eyesafe™ offers safety eyewear with designs that include flat frames, dust dam, close-fitting wrap style, and sealed eyewear. Frames are designed to provide “the perfect fit,” some with adjustable side arms, nose pads, and temple tips. A tighter fit offers improved performance and functionality. Let’s look at these four different frame designs.


Flat Lens

Flat frame safety eyewear is the most basic type of safety eyewear. The frame fits flat against the face with the addition of side shields. These models do not create an airtight seal, rather they allow for good air circulation in higher humidity environments. Flat frames are a good option in work environments where there may be minimal flying debris and eye impact hazards, but the direction of the dust is predictable. A disadvantage in flat-frame safety eyewear is that the simple design does not provide as much coverage, exposing the sides and corners to potential hazards. The flat frame design may also restrict peripheral vision along the edge of the field of vision if the side shields are not clear.

Dust Dams

Dust dam eyewear has a small ridge or “dam” around its upper edge to limit the amount of dust that can enter from above and get under it and into the eyes. Safety eyewear with dust dams are typically used in shop, automotive, and manufacturing. The simplicity of the frame design means that a close and tight fit can be an issue and will not be ideal for all hazards.

Close Fit

Close-fit safety eyewear, also known as wrap-style frames, is designed to fit closely to the face. This close fit provides better protection from blown dust which is less likely to get under the lens and into the eyes. Close-fitting safety eyewear is a good option for environments with dust and flying debris. Most wearers will comment on its comfort for long-term wear, but also complain of excessive fogging in humid environments due to less gap between the face and the frame.


Sealed close-fit safety eyewear has an even tighter fit than close-fitting safety eyewear as it includes a soft cushion seal. This type of safety eyewear typically has an adjustable strap to ensure a tight fit between the frame and the face. Close-fit safety eyewear may be a good choice for work in environments with small dust and dirt particulates. It is not a replacement for safety goggles where a chemical splash is possible, but they do provide superior protection compared to other safety glasses options. For environments with liquid and chemicals, choose close-fit safety eyewear with a chemical safety rating such as D3 Droplet protection. Fogging is a common issue with sealed safety eyewear. When working hard, the sweat around the eyes will evaporate and tend to condense on the lens. Manufacturers design frames to ensure the shape of the frame includes ventilation gaps to help minimize fogging.


Regardless of the style of safety glasses you select, ensuring the lenses are clean and the frame is in good condition will reduce the likelihood of dust getting into your eyes. Before using your safety eyewear, you should always clean the lenses — every time. Clean lenses do not fog as readily as dirty lenses. To clean your safety eyewear, use a cleaning solution designed for your safety eyewear, or a mild detergent such as dish soap. Eye safety is important in all hazardous workplaces. With so many choices of lens and frame type and style, there is sure to be a good choice to protect your workers and reduce the risk of eye injury at work. After all, the cost of an injury far exceeds that of protecting your employees.

Glyn Jones is a partner at EHS Partnerships Ltd. in Calgary. He is a consulting occupational health and safety professional with 35 years of experience. He is a regular safety conference speaker in Canada, and he provides program design and instructional support to the University of New Brunswick’s OHS certificate and diploma programs.

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