How to buy a fitover sunglass- what to look for and what to avoid.-

1. Buying a Fit-Over Sunglass
What You Should Know
The Vision Council of America reports that over 65% of people wear corrective eyewear. Less than 10% of
these people buy prescription sunglasses or photochromic lenses (lenses that darken when outdoors). A
lot of people choose to buy fit-overs. In fact, fit-overs have been around since the 1800’s and there as
popular today as they ever have been.
The evaluation process of fit-over eyewear is unlike that for fashion or sport sunglasses. This document
identifies the most common misconceptions consumers have about fit-over eyewear. If you’re reading this
it’s probably because you’ve decided to purchase a fit-over sunglass and want to educate yourself on the
category. That’s a wise decision because with fit-over sunglasses, a little bit of research goes a long way.
Far too many people who buy fit-overs based on conventional sunglass criteria, end up regretting it. A
beautiful paint job or sleek looking frame style soon goes unappreciated when the glasses are lacking in
features or comfort. Taking 10 minutes to educate yourself to the nuances of fit-overs is time well spent.
Although there’s several tertiary elements to a
good fit-over sunglass, there’s three key
elements you should review.
1) The Chassis
2) The Temples
3) The Lens System
It doesn’t matter if you’re appraising a low
priced pair from a drug store or an optical grade
model at an optometrists office. These three
fundamentals dictate overall performance with
any class of fit-over.
These are the three elements that fit-over
wearers comment on the most. Being aware of
them before you buy allows you to make an
“fit-overs for 50 cents” informed decision based on sound
Piqua Daily Call - July 14, 1935 fundamentals.
The most common gaffe people make when they’re buying a fit-over is that they forget why they’re buying
a fit-over. A fit-over performs a specific function. The performance of the glasses should be paramount. All
to often the products intended purpose is cast aside for what someone most likes aesthetically. I’ve been
designing fit-overs for over fifteen years and I’ll tell you right now, if you’re buying a fit-over to look
fashionable you’re out of luck. It’s virtually impossible to make a fit-over that works as well as it should
without sacrificing some style. All that glitters is not gold. Especially with fit-over sunglasses.
1

2. Chassis
The first thing you need to determine when considering a particular fit-over is the chassis, also known as
the frame. You need to know two things. The material it’s made from and if it has an undercarriage.
In my opinion’ the best material to use for the frame is Nylon12. This material is softer than hard plastics
such as TR90, which many brands are made of. A soft, pliable material is better for several reasons. First, it
cushions the fit-over when and if it comes into contact with the corrective eyewear it’s riding on. If you
wear a ‘hard’ plastic fit-over, it tends to be much less forgiving. It can clatter, jostle and can often cause
wear and tear on the prescription glasses. TR90 does have an advantage in that Nylon12 can’t be painted
like TR90 can due to its translucency. Some manufacturers take advantage by cashing in on the buying
motivations used when selecting a conventional pair of sunglasses. They know that consumers will be
drawn to the best looking frames, just as they would be when choosing a fashion or sports sunglass, so
they dazzle the chassis with beautiful colors and patterns. By attracting sales by aesthetics, they gloss over
the lack of features I consider compulsory. Doing so saves them money, which increases their profit.
The second frame feature to be reviewed is critical. The chassis must have an undercarriage. It’s
mandatory. If you look at a fit-over of any type, you’ll notice a ‘brow bar’ across the top of the frame.
That’s to stop light from penetrating from above. But if the bottom of the frame doesn’t have a return
‘scoop’ underneath each lens, light can penetrate from below. As much as 70% of light that reaches your
eyes can be reflected from the pavement, a road, sand or water for example. If this light is allowed to
enter from underneath the frame, the level of performance the fit-over delivers is compromised. The
Cocoons brand for example, has complete top, peripheral and underside protection. The majority of light
that does reach your eyes has been filtered through the front or side lenses. Everything else is blocked out.
Why is this a good thing? By precisely regulating the optical environment, the need for your eyes to
continuously adjust to variances in light conditions is eliminated. Your eyes are isolated from the elements.
After wearing a well made fit-over for about five minutes, many people experience a soothing, relaxed
state of mind. That’s because their eyes are getting a much needed break. They’re ‘cocooned’ so to speak.
Completely isolating your eyes can reduce eye fatigue and strain, allowing you to remain relaxed and
focused on the task at hand.
Why wouldn’t all fit-over manufacturers have return scoops? Once again it comes down to profits. If
there is an undercarriage to the frame, that means the fit-over will only accommodate specific shapes
and sizes of prescription glasses. The eyeglasses need to slot in between the top bar and undercarriage.
With no undercarriage, the fit-over simply has to accommodate the width of the eyeglasses. If the fit-
over is a little too small, the eyeglasses can protrude out of the bottom. That means that when a store
doesn’t have the precise size you need, you might end up buying a different size anyway as it seems to fit
well enough. That increases profits as the manufacturer doesn’t lose a sale. fit-overs with undercarriages
prevent them from being worn over eyeglasses that are too large. That means if the retailer doesn’t have
the size that fits like it should, you can’t buy one. That results is a lost sale.
2

3. So always check for an undercarriage. If
you’re buying online or in store, its easy
to see if there is a return beneath each
lens. The return should run from the
bridge of the frame all the way to the
outside edge of the lens cavity. Partial
undercarriages that don’t completely
encompass the lens cavity won’t deliver
the greatest performance either.
Undercarriage
The Temples
The temples, or ‘arms’ as many people tend to call them are as important, if not more so, than the
undercarriage. What’s critical is that the temples are adjustable. The temples must be able to be posed
into different positions based on the wearers preference. You wouldn’t believe the number of people that
have told me they stopped wearing their fit-overs because they became irritating, uncomfortable or didn’t
‘ride’ well.
A one piece, hard plastic temple that can’t be adjusted is an invitation for future disappointment. The fit-
overs will feel just fine when you first put them on for the day but an hour later the constant pressure of
the temple, in the exact same place, can cause discomfort. Remember, you’re going to be wearing two
pairs of glasses. It’s inevitable that the fit-over temple and the eyeglass temple will touch. It’s also common
sense that if you can’t adjust the temples, you can’t adjust the fit of the frame. Maybe the fit-over feels
loose or too tight. Tough luck if the temples can’t be customized.
When you’re wearing a pair of high quality, adjustable fit-overs, you shouldn’t even notice that you have
them on. You can test if you have a secure fit by looking down at your feet. If the fit-over slides forward…
you need to be able to adjust the temples.
3

4. The Lens System
As with all sunglasses, the lenses are the centerpiece of a fit-over. Poor quality front or side lenses will
deliver poor performance and reduce the products’ lifespan.
There are many lens materials available. Despite the hype that some manufacturers will bludgeon you
with, no lens is scratch or shatter proof. With a well designed fit-over there should be a set of front and
side lenses. Some fit-over glasses don’t have side shields. I would not recommend that type of product as
it’s almost the same as just wearing a regular pair of sunglasses on top of your prescription eyewear. You
definitely don’t get the tranquility you experience with a side shielded fit-over. That’s because untreated
light is rushing in and mixing with the filtered light, diluting the result.
You also want to make sure that the front lenses block 100% UVA & B as these are the rays most harmful
to your eyes. You need to make sure that the lenses are 100% polarized. Many brands claim 100%
polarization. Some are not. Usually if a brand does have 100% polarizing efficiency, they’ll point it out in
their marketing materials or product descriptions. Polarization is important as it eliminates glare.
The side lenses should have the exact same tint and transmission ratio as the front lenses. This creates a
more stable environment for your eyes. The side lenses need not be polarized. Polarization is for
eliminating glare. If you aren’t looking at something at the correct angle to experience reflected glare, you
won’t see any. That means you can’t see any glare out of the side lens because you’re not directly looking
through it. If I was designing a fit-over for a goldfish or a pigeon, I’d polarize the side shields since their
eyes are on the side of their heads. They’d have no problem staring directly out of the side lens. Some
companies even tout that their side shields are polarized. They’re not specially polarizing the shield
because they believe it has a benefit. Their side shields just end up polarized because they’re stamped out
of offcuts of the same material that the front lenses are made from.
Lastly you want to steer towards a product that has optically correct, injected side shields. Optically correct
side shields don’t distort your peripheral vision. If your peripheral sight line was distorted by a poorly made
side shield, it could be dangerous. You may misjudge where something is, such as a moving car.
Optically correct side shields are almost always injection molded. If the side lens on a fit-over seems to be
flat as opposed to contoured to the design of the chassis, there’s a good chance it’s not. A quick test to
determine if a lens is injection molded is to press your thumb firmly on the lens. If it flexes or completely
pops out, it’s not injection molded.
Happy Hunting.
About the Author: Mr. Kieran Hardy has been involved exclusively in the fit-over sunglass industry since 1997. Mr. Hardy continues
to drive the fit-over market as President of Live Eyewear Inc., the manufacturer of Cocoons fit-over sunglasses. Live Eyewear is
responsible for the overwhelming majority of fit-over innovations over the past fifteen years. Cocoons, arguably the world’s leading
brand of optical grade fit-over sunglasses, are distributed exclusively though eyecare professionals and better quality sporting
goods stores in over 30 countries. The Cocoons website is www.cocoonseyewear.com
4