Answers
Complete Perception, answered.
Every answer on this page is traceable to the HINDSIGHT Brand Book, the Edinburgh Napier research, or a public source we can cite. If a question is not listed here, contact us and we will add it.
01 — The product
Sizing, fit, and what you get.
What sizes do you sell?
HINDSIGHT glasses are available in one size.
Artemis: lens 54 mm · nose bridge 19 mm · temple to temple 148 mm.
Morpheus: lens 51 mm · nose bridge 20 mm · temple to temple 148 mm.
Will a hat, helmet, or hair get in the way?
Most hairstyles work seamlessly with HINDSIGHT glasses. If your hair is less than half an inch from your ears, you are good to go. For thicker hair, using a helmet or straps to flatten it ensures the right fit.
Why do I need to see behind me with these glasses?
Staying aware of your surroundings is key to safety, especially while cycling, running, rowing, and more. HINDSIGHT glasses enhance road awareness, allowing you to make smarter, safer decisions by providing full situational visibility.
Do the mirrors affect forward vision?
No. The mirrored zone is semi-transparent. It sits in your peripheral vision and lets you decide when to focus on what is behind, without obstructing your view of the road ahead.
Do all models include rear-view mirrors?
Yes. Every HINDSIGHT model includes the certified rear-view mirrored zone on both sides.
Do the glasses protect against UV?
Yes. The lens is UV 400 — UVA and UVB blocked to 400 nanometres. Category 3 daylight tint. As with any Category 3 sunglass, not for driving at night or in low-light conditions.
Are the lenses polarised?
HINDSIGHT does not currently offer polarised lenses. We are actively exploring polarisation, but it is not publicly available yet.
Are prescription lenses available?
HINDSIGHT does not currently offer prescription lenses. We are working on it, but prescription is not publicly available yet.
Can HINDSIGHT glasses fit over regular glasses?
HINDSIGHT glasses are designed to be standalone and will not fit over regular glasses.
How do I change my lenses?
Hold the frame and gently press the lens until it pops out. Store the removed lens in the provided pouch. Insert the new lens, aligning the raised bumps with the grooves in the frame. Ensure the mirror bend lines are parallel; adjust by rotating the lens if necessary. Wiggle the nose bridge gently to confirm the lens bumps are properly seated. If the mirror looks blurry, realign the bumps into the correct groove.
02 — The technology
How the lens works.
What is HINDSIGHT?
HINDSIGHT is the rear-view-in-the-lens ingredient brand. We make a semi-transparent mirrored lens that lets the wearer see forward and rearward at the same time, and we supply it to eyewear and activity-brand partners who carry the HINDSIGHT certification on the finished product.
What is Complete Perception?
The HINDSIGHT standard for a lens that delivers forward vision and rear-view vision simultaneously, through passive optics, with no compromise to either field.
How does the lens work?
A semi-transparent mirrored surface reflects a portion of incoming light and transmits the rest. The reflected portion gives you rear-view vision. The transmitted portion gives you forward vision. Both images sit in your peripheral field at the same time.
What is the 72.36 to 27.64 split?
The lens is divided at a proportion derived from the golden ratio (1:1.618). 72.36 percent is standard optical surface; 27.64 percent carries the mirrored zone. The mirrored zone is semi-transparent, so forward vision continues through it; shift focus and the rear-view appears.
Does HINDSIGHT use cameras or batteries?
No. HINDSIGHT is passive optics. There are no cameras, no batteries, no electronics, no screens.
03 — The research
What the study measured.
What did the Edinburgh Napier University research measure?
Research conducted at Edinburgh Napier University measured reaction time to rear hazards and the wearer's forward vision while wearing the lens. Headline findings: 139 milliseconds faster reaction time to rear hazards.
How should HINDSIGHT cite the research?
Always as "Research conducted at Edinburgh Napier University". The study is in draft form. We do not use the phrase "scientifically proven".
04 — The rear-view-in-the-lens ingredient brand
The HINDSIGHT certification.
Is HINDSIGHT a sunglasses brand?
No. HINDSIGHT is the rear-view-in-the-lens ingredient brand. The lens technology appears inside eyewear and activity products built by HINDSIGHT partners, carrying the HINDSIGHT certification on the finished product.
What is the HINDSIGHT certification?
A button mark applied to certified partner products. It signals that the product meets the Complete Perception standard. The mark is a circle divided at a proportion derived from the golden ratio.
Is HINDSIGHT comparable to MIPS or Gore-Tex?
The structural model is comparable. MIPS certifies rotational-impact protection inside helmets. Gore-Tex certifies a waterproof membrane inside garments. HINDSIGHT certifies Complete Perception inside lenses. All three are ingredient brands operating across multiple host-brand partners.
Which categories does HINDSIGHT certify?
Nine: cycling, running, e-mobility, military, law enforcement, snow sports, water sports, equestrian, and first responders.
How do brands become HINDSIGHT certified?
Partner brands begin with a briefing call with the HINDSIGHT partnerships team. Certification is product-specific and follows technical review.
05 — The company
Who we are.
Who founded HINDSIGHT?
HINDSIGHT was founded by Alexander Macdonald, a physicist, and co-founded with Callum Skinner, Rio 2016 Olympic gold medallist.
Where is HINDSIGHT based?
HINDSIGHT is a United Kingdom-based company. Partner brands operate internationally.
What was the Kickstarter campaign?
HINDSIGHT's original direct-to-consumer product was funded on Kickstarter, raising over one hundred thousand pounds from more than six hundred backers in thirty-eight countries.
Why did HINDSIGHT pivot to an ingredient brand?
Because Complete Perception is a property that belongs in every category of performance lens — not in a single direct-to-consumer product. Certifying partner products is the right shape of the company.
06 — Shipping & returns
Getting your order.
What is your returns policy?
Customers must contact us within 14 days of delivery if an order arrives damaged or includes the wrong product. We will issue a refund after our warehouse receives the return. If an error was made, you are not happy with the product, or you received a damaged product, please get in touch and we will make it right.
How are international customs and taxes handled?
HINDSIGHT is not responsible for customs duties and taxes applied to your order. All fees imposed during or after shipping are the responsibility of the customer (tariffs, taxes, etc.). Your order may attract duty and tax on arrival; this does not constitute a reason to refuse delivery or its return.
What if my order arrives damaged?
HINDSIGHT is not liable for products damaged or lost during shipping. If you received your order damaged, please contact the shipment carrier to file a claim. Save all packaging material and damaged goods before filing a claim.