From Bertoni Eyewear web site:
This line has Photochromic anti-fog lenses which change colour intensity automatically depending on the UV light, guaranteeing an excellent visual performance. The photochromic lenses protect the eyes when out in the sun or in any weather condition. Plus the lenses are treated with a special resin which removes the condensation which forms on the surface of the lens when passing from hot to cold. The lens can change colour in only 8 seconds when passing from light to dark, and 35 seconds when passing from dark back to its light colour. The frame of this line is in nylon so they will never change shape and are highly resistant to impacts.
I’ve been looking for a while for the ideal glasses for dusty conditions and even been tempted to go the MX mask, but unless I’m wearing a full face helmet that seems a little bit excessive.
The Bertoni F120A are technical sport glasses with windstop and photochromic antifog lenses. They feature a strap rather than sidearms and soft padding around the frame seals your eyes from wind and dust. Small air vents still allow a certain amount of air circulation inside the glasses avoiding condensing on the lenses.
Lenses material is polycarbonate, pretty light and resistant. These lenses have photochromic characteristics, meaning they will change their transmission rate (i.e. darkness) with the amount of light. Out of the box and away from the sun, lenses look just clear. Once exposed to direct light they quickly change color.
According to the manufacturer the response time is about 8sec going from clear to dark and 35secs going from dark to clear. In the shade the lenses are completely clear, allowing a good view even at night. In the sunlight the color becomes pretty dark, showing an impressive range.
Lenses have also been treated with antifog process. This is pretty important for any kind of sport glasses, but much more for this kind of enclosed model.
RIDING IMPRESSIONS
Summer is a great time for riding as there are many more daylight hours and weather is great, but very often trails get dusty. Not a big deal when riding alone, but becomes a problem in groups or worse during races.
These glasses are not significantly heavier than regular sunglasses, but offer a much higher level of protection from the elements, such wind and dust.
The strap is easily adjusted, fairly soft and once worn under the helmet straps is unnoticeable. It keeps the glasses in place without much pressure.
The padding is made in soft spongy material and provides a good contact with the rider’s face. It does absorb moisture and sweat while riding.
Since I’m not a fast climber my glasses always fog while climbing. It is not the case with the F120A. After about 1 hour of riding some condensing was present on the inside of the lenses when stopped – not fogging, but moisture. That promptly disappeared as soon as I started moving again.
The photochromic feature also seems to work pretty well. You actually don’t notice you are wearing glassses: In the shady areas they are clear and become dark pretty quickly in the sunny sections.
Overall comfort is good and after 3 hours ride you don’t notice you are wearing goggles. The only drawback I could find is that in order to remove the glasses you have to open the helmet buckle and in some cases the helmet. This may not be so practical especially when wearing full face helmet. But in those cases a full MX mask may be best suited.
CONCLUSIONS
According to the manufacturer this is the only light mask available on the market with photocromic lenses. I find this product a good compromise between light technical sunglasses and an MX mask. The Bertoni F120A comes with care instructions and a soft bag that can be used to clean the lenses: retail price is $75.
http://www.bertonieyewearusa.com
