Prescription Safety Glasses Lens Guide

Safety glasses are essential to protecting one of our most valuable assets: our vision. With a wide variety of materials, tints, coatings, and finishes, it can be a bit tricky to narrow down which lenses you need to suit your needs. That’s why we have created this safety lens guide to help you select the perfect set of lenses to protect your eyes throughout all of your weekend projects or long work days.


ANSI Z87.1 Approved Prescription Safety Lenses 

The ANSI Z87.1 standards for optical clarity and impact resistance provides specific requirements on eye and face protection allowed in the workplace.  The “American National Standard Practice for Occupational and Educational Eye and Face Protection” implemented the ANSI Z87.1 standard to obligate employers to enforce the use of appropriate eye or face protection when exposed to hazardous materials, liquids, vapors, chemical or other harmful substances.   The ANSI Z87.1 is the industrial standard for eyewear, and all of the information to follow on selecting safety lenses pertains to ANSI Z87.1 certified lenses.

 

Prescription Safety Lens Types

A lens type refers to which type of vision needs corrected. In today’s market, there are two main types of lenses, single vision and multifocal.

Single Vision: These lenses will correct for nearsightedness or farsightedness, helping you see either up close or far away, whichever your doctor determines you need.

Multifocal: A multifocal lens will correct for both near and farsightedness all in one lens. A multifocal prescription will have numbers in the ADD column on your prescription. A traditional multifocal lens would be a lined bifocal in which the visible line separates the top portion of the lens used for seeing at distance from the lower portion of the lens which contains magnification for reading up close.

The modern multifocal is known as a progressive lens, or a lineless bifocal. A progressive lens eliminates the line which signifies an abrupt change and instead gradually progresses from distance to reading magnification. Not only is this gradual progression easier for your eyes to adapt to, it also provides intermediate (computer distance) vision. 

If your work requires a mix of seeing far away and reading things up close, you will likely want to invest in progressive safety lenses. For example, if you will be driving from job site to job site and then reading blueprints, the ability to read street signs and text up close means you would enjoy the benefits of a progressive lens.

The following diagram visually explains the difference between bifocals and progressives: 

 

 

Safety Lens Materials

In addition to selecting a vision type, you may also be faced with picking a lens material. Today, there are three common lens materials, all of which can be safety approved. Regardless of which lens material you select, when you purchase ANSI eyewear and select any of the following materials, your lenses will feature an ANSI Z87.1 certified stamp in the upper temple corner of the lens.

Polycarbonate: Polycarbonate is the industry’s most popular lens material as it is lightweight, impact-resistant, optically clear, and is by nature 100% UVA/UVB blocking.
Most mild to average prescriptions work best with Polycarbonate which is why approximately 90% of patients select this material.

Trivex: Trivex is similar to polycarbonate in the sense that it is shatterproof, UVA/UVB blocking, and lightweight. Trivex does boast better optical clarity than polycarbonate, which is why it tends to be labeled as more of a premium lens material. It is also slightly more scratch resistant than polycarbonate.

High Index: High index material is another plastic-based lens material, but due to higher density this material was specifically designed with strong prescriptions in mind. High index lenses are available in 1.67 and 1.74 densities, and to simplify your lens buying process, our expert lab technicians will select the best density to best correct your vision.

 

If you still can’t decide which lens material is best for you, feel free to reach out and one of our prescription experts would be happy to assist you in picking the perfect material to suit your needs.

 

Prescription Safety Lens Surfacing Techniques

There are currently two methods to surfacing prescription lenses: conventional and digital. While conventional surfacing is the original, for safety lenses, this method is not recommended and you should stick to digital surfacing.

Digital lenses are always going to be recommended for prescription safety glasses because digital surfacing eliminates peripheral distortion.  This allows your prescription to be accurate to the nearest 0.01 diopter (versus 0.25 with conventional surfacing) from edge to edge of the lens.

This digital technology is most beneficial in high wrap prescription safety sunglasses that have a curved lens as opposed to a flat lens.  Non-digital lenses have more of an optical center than digital lenses, which means you can get some peripheral distortion with a non-digital lens as your prescription won’t be completely accurate from edge to edge.

  

Prescription Safety Lens Tints

A standard sunglass lens is a non-polarized, tinted lens, made of any of the materials listed above. While there are almost infinite lens tint choices, here are the most popular for safety use:

When to Select a Neutral Lens (Grey Base):  If you typically wear your prescription safety glasses or sunglasses in bright full sunlight conditions a grey base lens is usually going to be your best options as grey base lenses cut out harsh glare and offer superior visual clarity in bright, full sunlight conditions.  Grey base lenses are neutral lenses that lets you see true color as it is without altering it which is what high contrast lenses do.  Grey base lenses will darken the environment without making it high contrast, which the eye translates as light.  A grey based lens will be ideal for bright conditions and all day wear as it will put less stress on the eye by dulling the light that is transmitted. 

Grey: This is the most popular sunglass lens tint due to its neutral color perception and darkness. Many people enjoy grey lenses for everyday use as it does not alter color perception. Those with light sensitivity tend to prefer lenses with grey base tints because they are naturally darker than other more contrast-enhancing tints. 

Grey-Green: Ray-Ban is the company that really put grey-green on the map with their G-15 tint. Grey-Green is a great lens tint for those who like grey lenses but want a little bit of contrast enhancement. The green undertones help enhance contrast without drastically altering color perception.
 
When to Select a High Contrast Lens (Brown, Amber, or Yellow Base):  If you typically wear your prescription safety glasses or safety sunglasses in varying light conditions where you are in and out of shadows, require increased depth perception, or improved definition between objects a high contrast lens will usually give you the best optical experience.  Brown, copper, rose, and amber base tints are all going to be high contrast lenses that amplify color making objects more defined and easier to differentiate.  

Brown: This is the second most popular lens tint for everyday use, and a top pick for sports use due to contrast enhancement and neutral aesthetics. Brown lenses are as great for everyday use as they are for active lifestyles as they enhance contrast, allowing you to differentiate between objects easier. Those with light sensitivity can still enjoy a brown lens, but we recommend pursuing a dark brown, or adding a mirror finish to further darken your lens.

Amber or Yellow: Amber is essentially a brown lens with more yellow undertones, but the tint itself will vary from company to company. Some ambers are a dark brownish-yellow, while others are quite light which more closely resemble honey-colored fossilized amber. Yellow is popular among those who need a low-light lens which brightens surroundings. Yellow lenses are popular for safety and shooting.
 
When to Select a Photochromic/Transitions Lens: If you will be using your new safety glasses in variable light conditions such as out in the full sun one minute and inside the next, you are a perfect candidate for transitions lenses. Transitions lenses are extremely popular in safety glasses, as they serve as eyeglasses and sunglasses, all in one. A photochromic lens will lighten and darken according to the amount of UV light present. Many patients know these lenses as Transitions lenses, which is the name of the brand who really put photochromic lenses on the map. A traditional photochromic lens will be completely clear indoors, or at night, and will darken in direct sunlight. Because the tint of the lens adapts to sunlight, this reduces eye fatigue. We use Transitions branded lenses, which come in 3 different versions:

      • Transitions Adaptive: This is known as the original Transitions lens, transitioning from clear to grey or brown.

      • Transitions Xtractive: If you intend to do any driving in your new Transitions lenses, you will want to opt for the Xtractive version. Traditional Transitions lenses will not darken in the car while driving because modern windshields have UV blockers present, which prevent the chemical reaction necessary to darken your lenses. Xtractive is the exception! Not only will these lenses work while driving, they get a bit darker than the original Transitions lenses too, making them ideal for those with light sensitivity.
    • Transitions Vantage: Transitions Vantage lenses are great for patients seeking a versatile lens but who still need polarization in their sunglasses. When these lenses are clear, the polarization filter will not work, which allows you to use your computer uninhibited, but once the lenses darken in the sun, the polarization works in full force.

 

Sunglass Lens Treatments

Polarization: A polarized lens drastically reduces glare from the sun as it reflects off of bodies of water, ice, snow, or pavement. This type of glare can actually be more harmful to our eyes than the light which comes directly for the sun! Polarized lenses also tend to make colors a bit more crisp and vibrant, and most eye doctors recommend polarization as it is better for the eye’s overall health. The only tints that polarization won’t work in are clear lenses.

  

If you spend a lot of time looking at a screen for work, you will likely want to avoid polarization. Most people purchasing safety eyewear prefer non-polarized lenses unless your job has you spending time near the water, or in places where glare is prominent (cities with tall windowed buildings, cars, etc).

Anti-Reflective Coating: An anti-reflective, or A/R, coating is applied to the front side of any lens which is clear or goes clear (like Transitions lenses) or to the back side of any sunglass lens. These coatings are designed to improve optical clarity by blocking annoying reflections from invading your lenses.

A front A/R on a clear safety lens makes your optics crisper, and also allows others to see your eyes when they look at you, rather than seeing the reflections in your lenses. When applied to the back side of a lens, an A/R finish prevents reflections from light that may seep in from the frame’s top, bottom, or most commonly, sides. While this is optional for standard grey, brown, copper, etc sun lenses, any time a mirror finish is applied to the front of the lens, a backside A/R is automatically included.

Hard Coat: Some labs offer hard coats which are scratch-resistant coatings. Because safety glasses tend to take a bit of a beating, especially in professions where dust and debris are common in the air, a hard coat will improve the longevity of your prescription eyewear.

Mirror Coating: Mirror coatings are the hyper-reflective treatments applied to the front of a lens, and they are beneficial for a number of reasons, the first of which being aesthetics. Many people enjoy mirror finishes as they make a lens totally opaque, meaning that lookers on cannot see through the lenses. Aesthetics aside, mirror finishes also enhance contrast, repel glare, and darken the lens. Mirror finishes come in various colors from subtle black and bronze mirrors to vibrant blue, orange, and purple mirrors.

Whenever a mirror coating is applied to the front of a lens, a backside anti-reflective coating will be applied to the back of a lens. Because mirror finishes are so reflective, the backside A/R prevents reflected light from becoming trapped on the inside of the lens, which can be distracting.

Fun fact, you can also add a mirror coating to a transitions lens! At their clearest, the mirror will look like a standard A/R coating, but when the lenses darken, you’ll have a darker lens that lookers on can’t see through. 

 

Anti-Fog: If you will be working in a humid climate, an anti-fog coating is likely an excellent add-on for you. This coating is applied to the back of your lenses to keep your lenses from fogging up.  

 

 

If you have any other questions about safety lenses, feel free to give us a call at 888-507-1230, or send us an email at info@saltcityoptics.com and we would be happy to further assist you in selecting the perfect pair of prescription safety glasses.