OD & OS
OD identifies the right eye. OS identifies the left eye.
Understand your eyewear. Choose with confidence.
Safety Eyewear Resource Guide
A practical reference for lens materials, prescriptions, coatings, standards, and frame measurements.
Use this guide to understand the terms and options you may encounter when selecting prescription safety or everyday eyewear.
Lens Fundamentals
Lens Materials and Digital Options
Compare impact resistance, optical clarity, comfort, and prescription performance.
Trivex offers impressive impact resistance and durability while remaining lightweight and comfortable. Its high Abbe value helps reduce chromatic aberration and halos around lights, supporting sharp, distortion-free vision. Trivex also offers useful chemical resistance, including resistance to substances such as acetone and isopropyl alcohol.
Polycarbonate is a strong, high-impact-resistant material with scratch resistance, excellent light transmission, built-in UV protection, weather resistance, and the ability to withstand high temperatures without melting or deforming. Its insulating properties and durability make it useful in oil and gas, automotive, agriculture, aerospace, construction, manufacturing, medical, energy, government field work, and other environments where eye protection is a priority.
High-definition lenses use digital manufacturing to improve clarity, peripheral vision, night vision, and the usable visual field while reducing distortion and addressing higher-order vision aberrations. They can be especially useful for medium-to-high prescriptions, significant astigmatism, progressive wearers, and wrap-frame users. Progressive designs may provide a wider reading channel and crisper distance vision, with smoother adaptation and less head movement. Safety Rx manufactures high-definition lenses for demanding users, including NASA astronauts, and offers wholesale pricing that may be substantially below retail.
Protection & Compliance
Safety Versus Non-Safety Eyewear
Regular prescription glasses improve vision; certified safety eyewear is designed to protect vision from workplace hazards.
Safety glasses are designed for hazards such as flying metal or glass, impact, sparks, chemicals, distorted lighting, and other workplace exposures. They require impact-resistant frames and lenses plus appropriate side protection. Prescription safety eyewear can also correct nearsightedness, farsightedness, and astigmatism so employees can work more safely, efficiently, and effectively. Safety Rx manufactures prescription and non-prescription safety lenses and frames tested to applicable ANSI Z87.1 high-mass and high-impact requirements in its in-house optical laboratory.
Regular eyeglasses correct vision problems such as nearsightedness, farsightedness, and astigmatism, but they are not designed to protect against chemical exposure, flying debris, or other workplace hazards and generally lack safety-rated side protection.
The American National Standards Institute coordinates standards intended to support product safety, quality, and performance. For occupational prescription eyewear, the relevant requirements include qualification for high-impact, high-velocity, and high-mass testing. Testing includes more than traditional drop-ball testing and may involve full frame-and-lens assemblies subjected to impact speeds around 151 feet per second as part of the manufacturing qualification process.
Protecting Eyes at Work
Why the Right Protection Matters
Workplace eye injuries are common, costly, and often preventable.
The National Institute for Occupational Safety and Health reports that about 2,000 U.S. workers sustain job-related eye injuries requiring medical attention each day. Safety professionals and eye doctors estimate that appropriate protection can prevent or reduce the severity of roughly 90% of eye injuries.
OSHA has reported that workplace eye injuries can cost more than $300 million annually through lost productivity, medical treatment, and workers’ compensation, before accounting for recovery-related missed work.
- No eye protection was worn
- The wrong protection was selected
- Limited or uncomfortable choices reduced use
- Online orders produced fitting or remake problems
- Measurements or adjustments were incorrect
- Workers did not believe protection was required
- Employer did not require proper eye protection
- Lack of proper fitting
Prescription safety eyewear is an investment in safety—not just another pair of glasses. It helps protect vision, reduce workplace injuries and OSHA recordables, improve productivity, and may help prevent permanent eye damage or vision loss.
Optical measurements are made in millimeters, so accuracy matters!
Prescription Designs
Types of Prescription Lenses
Different lens designs support distance, near, intermediate, and progressive vision needs, including solutions for office work, control rooms, computer use, room-distance tasks, and reading.
Single-vision lenses use one prescription power, usually for distance or near vision. They can help the wearer see clearly at one primary range, but they do not provide separate distance and reading zones in the same lens.
Bifocals contain two optical powers. The upper portion is generally used for distance, while the lower portion supports near vision. A visible line separates the two zones.
Progressive lenses gradually increase magnification from top to bottom, supporting far, intermediate, and near vision without visible dividing lines. The design provides a smoother transition when looking from distant objects to intermediate work or reading.
Trifocals contain distinct zones for distance, intermediate vision at approximately arm’s length, and near tasks. They are often used by people with advanced presbyopia who need additional support for reading or computer work.
Light & Color
Photochromic, Polarized, Clear, and Tinted Lenses
Lens color and UV response influence glare control, visual comfort, and outdoor performance.
Photochromic lenses automatically darken in direct sunlight or UV exposure and return toward clear indoors. They reduce glare and bright-light discomfort while combining clear indoor wear with non-polarized sun protection in one lens. Multiple transition colors may be available.
Polarized gradient lenses are darker at the top and lighter at the bottom. Some designs respond to sunlight or UV exposure and return toward clear indoors while reducing glare and preserving a lighter lower viewing area. Color choices may be available.
Polarized sun lenses reduce glare and eye strain, improve outdoor detail, and enhance visual comfort for activities such as driving, fishing, boating, and other outdoor recreation. They are available in gray or brown lens colors, each offering unique visual benefits. Gray lenses provide true color perception while reducing overall brightness, making them ideal for driving and everyday outdoor use. Brown lenses enhance contrast and depth perception, making them a great choice for activities where distinguishing details and changing terrain is important.
Clear lenses are colorless and suitable for everyday indoor use. Tinted lenses have a colored treatment that reduces incoming light and can provide UV protection. Tint intensity is available in Light (1), Medium (2), and Dark (3) levels, allowing you to choose the shade that best fits your work environment, outdoor activities, and personal preference.
Lens Treatments
Coatings for Clarity, Durability, and Easier Care
Coatings can address reflections, fog, scratches, digital light, fingerprints, and water.
Anti-reflective coatings reduce reflections from sunlight, vehicle lights, ceiling lights, and cameras. By making lens reflections less visible, they can reduce eyestrain, halos, and distraction while helping other people see the wearer’s eyes more clearly. They are especially useful on prescriptions that naturally reflect more light.
Permanent anti-fog treatment helps lenses remain clear across hot-to-cold and cold-to-hot transitions, including mask use, moving between air conditioning and outdoor heat, manufacturing environments, and cold-storage facilities. Clearer lenses improve visibility where eye safety is a priority.
A super-tough thermally cured scratch coating adds a protective layer that improves resistance to everyday scratching and damage. It can extend useful lens life, although no coating can prevent every scratch.
Blue-light treatments are designed to reduce selected blue-light exposure from computers, phones, and other digital devices. They may help with eyestrain, headaches, fatigue, and symptoms associated with prolonged close-focus screen use.
Oleophobic treatments help resist oils, smudges, and fingerprints, while hydrophobic coatings repel water to improve cleaning and maintain clearer vision in wet conditions. Together, they help keep your lenses cleaner and easier to care for.
Read Your Prescription
Understanding Eye-Doctor Abbreviations
These common terms describe each eye, corrective power, astigmatism, reading power, and optical-center placement.
SPH
Sphere is the lens power needed for vision correction. Negative values indicate nearsightedness; positive values indicate farsightedness. Larger absolute values represent stronger prescriptions.
CYL & Axis
Cylinder identifies the amount of astigmatism correction. When cylinder is present, Axis specifies its orientation.
ADD
Add is the additional magnification used for the reading portion of a multifocal prescription.
PD
Pupillary distance is measured in millimeters between pupil centers. It positions the optical centers correctly and may appear as one number, such as 64 mm, or dual values, such as 32/33.
Why Accuracy Matters
Accurate prescription values and measurements support clear, comfortable vision and proper optical alignment.
Frame Measurements
Understanding Your Frame Size
Most frames print three measurements in millimeters on the inner temple arm or near the nose bridge.
For a marking such as 49 □ 22 150:
- 49 — lens width, commonly 40–62 mm
- 22 — bridge width, commonly 14–24 mm
- 150 — temple-arm length, commonly 110–150 mm
Use existing frame measurements as a starting point, then confirm coverage, bridge fit, temple length, and comfort—especially for safety eyewear.
Frame Size Diagram
Locate the key measurements used to compare frame dimensions.
Find the Printed Size
Check the inner temple arm or bridge area for the frame’s measurement sequence.
Frame Materials
Frame Materials & Construction
Choosing the right frame material is just as important as selecting the right lenses. Each material offers unique advantages in weight, durability, flexibility, comfort, and appearance. Whether you’re selecting eyewear for work, everyday use, or recreation, understanding the differences can help you find the best fit for your lifestyle.
| Material | Weight | Durability | Corrosion Resistant | Best For |
|---|---|---|---|---|
| Metal | 3 out of 5 | 4 out of 5 | 4 out of 5 | Everyday wear, adjustable fit |
| Zyl (Plastic/Acetate) | 4 out of 5 | 4 out of 5 | 5 out of 5 | Comfort, fashion, everyday use |
| Titanium | 5 out of 5 | 5 out of 5 | 5 out of 5 | Sensitive skin, nickel allergies, premium comfort |
| Stainless Steel | 4 out of 5 | 5 out of 5 | 5 out of 5 | Industrial environments, long-term durability |
Metal Frames
Metal frames are a popular choice for their durability, slim profile, and adjustable fit. They are available in a variety of finishes and styles, making them suitable for both safety and everyday eyewear. Many metal frames feature adjustable nose pads for a customized and comfortable fit.
Zyl (Plastic/Acetate) Frames
Zyl, also known as acetate, is a lightweight, durable plastic material that offers excellent comfort and style. Available in a wide variety of colors, patterns, and shapes, Zyl frames are an excellent choice for everyday wear while providing the durability needed for many work environments.
Titanium Frames
Titanium frames are among the lightest and strongest eyewear materials available. They offer outstanding durability while remaining exceptionally comfortable for all-day wear. Titanium naturally resists corrosion, making it an excellent choice for humid environments and demanding workplaces.
Because titanium is nickel-free, it is a preferred choice for individuals with nickel allergies or sensitive skin. Many wearers choose titanium to reduce the risk of skin irritation while enjoying a lightweight, premium-quality frame.
Stainless Steel Frames
Stainless steel frames offer an excellent combination of strength, durability, and corrosion resistance while remaining lightweight and comfortable. They are well suited for everyday use as well as industrial work environments where long-lasting performance is important.
Safety Rx proudly offers Art-Craft Optical stainless steel frames, manufactured in the United States and recognized for their quality craftsmanship and commitment to American manufacturing.
Which Frame Material Is Right for You?
- Choose Metal if you want a durable frame with a classic appearance and adjustable fit.
- Choose Zyl (Plastic/Acetate) if comfort, color options, and style are your priorities.
- Choose Titanium if you prefer an ultra-lightweight frame or have a nickel allergy or sensitive skin.
- Choose Stainless Steel if you’re looking for exceptional durability, corrosion resistance, and American-made quality.
Style, Coverage & Fit
Choosing the Right Frame for You
Measurements are the starting point. Face shape, workplace hazards, side coverage, frame material, and personal comfort all help determine which frame is right for you.
Prescription Safety Glasses
ANSI-rated protection with prescription clarity and a professionally fitted frame.
Explore frames
Wrap-Around Frames
Extended coverage for active work, wind, dust, and changing viewing angles.
Explore wrap-around frames
Outdoor & Specialty Frames
Prescription options for fishing, hunting, driving, motorcycle use, and bright environments.
Explore outdoor eyewear
Need Help Applying This Information?
Safety Rx specialists can help interpret prescriptions, compare lens materials and coatings, and select properly fitted safety eyewear.
Bring your questions, prescription, and workplace requirements.