Standard safety glasses are designed to protect against light to moderate impact and flying particles. Flying particles may include wood or metal debris, light dust, blood, or other body fluids, etc. Safety glasses must have shatterproof lenses, impact-resistant frames and provide side protection. Detachable side protectors (e.g. clip-on or slide-on shields) are acceptable if they meet the ANSI requirements. Prescription safety glasses are available through your optometrist and must also meet these criteria.

Safety glasses are available in a wide variety of styles and (lens) colors. Styles should be chosen that employees like, and will therefore wear. Lens color should also be considered when selecting safety eyewear to help reduce glare, eye strain, color distortion, and improve visibility in certain conditions.

Caution should be exercised in the use of metal frame safety glasses in electrical hazard areas.

Non-side shield safety glasses are available for frontal protection only, but are not acceptable eye protection for the sources and operations involving "impact."

The energy emitted from lasers is highly concentrated and can cause permanent eye injury. Although engineering controls are preferred to reduce hazards from the laser beam, it may be necessary to use laser safety eyewear when engineering controls are inadequate. Laser safety eyewear must be worn in areas where unenclosed Class 3b or 4 lasers are operated. Laser eyewear filters or absorbs light of a specific wavelength, while maintaining adequate light transmission for other wavelengths. The absorption capability of the filtering media is called the optical density (OD). The OD is always expressed as a factor of 10. An OD of 5 means the filter has reduced the power of the beam to 1/100,000 of its original power. The required OD is the minimum OD necessary to reduce the beam to a non-hazardous level. The OD of the eyewear has to be at least equal to, or greater, than the required OD for each wavelength. The eyewear must be labeled with the optical density of the lens and the wavelength that it protects against.

When choosing appropriate laser eyewear, time is also a consideration. The length of time the eyewear will protect your eye before the beam goes through, and how much time you will have to react if you are hit with a direct beam are factors. According to ANSI, protective eyewear shall exhibit a damage threshold for a specified exposure time (typically 10 seconds). The eyewear shall be used in a manner so that the damage threshold is not exceeded in the worst-case exposure situation. The main points to consider when selecting eyewear for a specific laser includes:

• Wavelength
• Optical density
• Laser beam intensity
• Luminous transmittance
• Damage threshold
• Comfort
• Lenses

For more information on selecting laser protective eyewear, refer to the laser manufacturer's recommendations and instructions and/or review Environmental Health & Safety's Laser Safety Program.

Vinyl-framed goggles of soft pliable body design provide adequate eye protection from many hazards, such as impact, chemical splash, dust, sand, and debris. Goggles are available with perforated, port-vented, or non-vented frames. Single-lens goggles provide similar protection to spectacles and may be worn in combination with spectacles or corrective (prescription) lenses to ensure protection along with proper vision. Like safety glasses, goggles are impact-resistant and are available with tinted lenses.

Environmental Health & Safety strongly recommends the use of safety goggles, rather than safety glasses, for all personnel working in laboratories with chemicals or human bodily fluids.

Welders/chippers goggles provide protection from sparking, scaling, or splashing metals and harmful light rays. Lenses are impact-resistant and are available in graduated shades of filtration. Filter lenses must meet the requirements for shade designations as outlined in the OSHA regulations and ANSI standards. Tinted and shaded lenses do not filter lenses.

Face shields are considered secondary eye/face protection and provide general protection to the entire face for a variety of hazards, such as flying debris, chemical splash, arc flash, UV radiation, and extreme heat. Face shields must be used in combination with goggles (primary eye protection) when there is a potentially significant chemical splash hazard, especially where highly toxic chemicals or corrosives are used. Face shields must be worn over safety glasses or goggles (primary eye protection) whenthere is a potentially severe exposure to flying fragments or objects, hot sparks from furnace operations, potential splash from molten metal, or extreme temperatures.

Welding helmets/shields must be provided to protect the worker's eyes and face from infrared or radiant light burns, flying sparks, metal splatter, and slag chips encountered during welding, torch brazing, torch soldering, resistance welding, bare or shielded electrical arc welding, and oxy-acetylene work.

The shield assemblies consist of a vulcanized fiber or glass-fiber body, a ratchet or button type adjustable headgear or cap attachment, and a filter and cover plate holder. Newer technology offers auto-darkening lens capabilities. For manual filtered lens selection, start with a shade that is too dark to see the weld zone, then switch to a lighter shade that gives a sufficient view of the weld zone without going below the minimum shade allowed. In oxy-fuel gas welding or cutting where the torch produces a high yellow light, use a filter lens that absorbs the yellow (sodium line) in the visual light of the (spectrum) operation. Guidance on appropriate filtered shades for various operations is available here.

Welding helmets or filtered face shields should only be used over primary eye protection (i.e. safety glasses or goggles). Follow the manufacturer's instructions.

• Clear - for general indoor applications.
• Gray - for outdoor applications where light and glare can cause eye strain and fatigue. Provides good color recognition.
• Mirror - same purpose as gray lens, yet allows more visible light through the lens for indoor/outdoor use. Reduces glare from artificial light.
• Gold/Blue/Silver Mirror - for outdoor use where sunlight and glare cause eye strain and fatigue. "Mirror" coating reflects light, reducing the amount of light that passes through the lens.
• Dark Green - general-purpose protection from glare and UV radiation.
• Brown - for outdoor applications where sunlight and glare cause eye strain and fatigue. Meets color traffic signal recognition requirements.
• Vermilion (pink) - enhances contrast while reducing all color equally for optimum color recognition. Ideal for indoor inspection.
• Amber - blocks the blue portion of the visible light spectrum, creating maximum contrast enhancement, particularly in low light.
• Filtered shades (green to brown) - protect against ultraviolet and infrared radiation generated when working with molten metal, and in welding, cutting, soldering, and brazing operations. 

1. Shades 1.5-3 for torch soldering
2. Shades 3-4 for torch brazing
3. Shades 3-6 for cutting applications
4. Shades 4-8 for gas welding
5. Shades 10-14 for electric arc welding