Many studies have been done on the effects of exposure of the human eye to bright sun light and glare. These effects include short term fatigue due to eye strain as well as more serious long term conditions which may develop such as cataracts. By decreasing the eyes exposure to bright sun and glare, you can expect to reduce eye fatigue as well as the potential to develop more serious longer term eye conditions.To better understand the solutions one must understand the difference between sunlight and glare. Sunlight can be defined as the light provided directly from the sun to ones eyes. Glare can be defined as light which is reflected off of surfaces or objects.The problem is determining the best way to reduce bright sun and glare for the individual activity, in this case, motor sports. The more common solutions are tinted sunglasses worn inside a helmet or a tinted/smoked shield worn on a helmet. Each employ similar technologies of tinting which reduces the total amount of light reaching the eye and ones actual ability to see.This presents several issuesSunglasses inside of a helmet can pinch the head and fog up.Sunglasses inside of a helmet may present a safety risk in the event of a crash.Non polarized lenses must reduce the total amount of light reaching the eye to be effective including the light needed to actually see.Polarized sunglasses worn inside of a polycarbonate helmet shield may develop spectral effects showing imperfections in the shield. (More on this later).Smoked shields must be removed in low light or night conditions and storage can become an issue.Polarized sun lenses are unique in their ability to eliminate up to 80% of glare and still allow for optimum amounts of light to reach the eye for vision. Placing the polarized lens on the outside of the helmet shield also eliminates spectral effects between the polarized lens and polycarbonate shield. This not only provides for reduced eye strain and fatigue due to significant glare elimination, but also provides one’s ability to see better for longer periods of time.What about one’s ability to see oil or fluids?One of the most common questions when it comes to using polarized lenses in motor sports activities is “Can you see oil or fluids on the road surface with a polarized lens?”To help answer this question we performed a short informal testStationary Test:We placed 10oz of 10W40 motor oil on a black top surface at 8 am. From a distance of 10 ft to the east of the oil, sun at our back, the oil was virtually non visible to the naked eye. When the polarized lens was used, a vivid dark puddle appeared clearly.From a distance of 10ft to the west of the oil, sun now in front of us, the oil displayed a sharp reflection to the naked eye. When the polarized lens was used, the sharp reflection once again became a vivid dark puddle.Without polarized lens With polarized lensMoving 5 mphWe then, without the polarized lens, made a pass at 5mph from the east past the puddle. The oil was non visible until the rider was directly over top of it. This same 5mph east to west pass with the polarized lens resulted in seeing the oil as a vivid dark spot in the road surface well before reaching it. Switching direction, the oil produced a sharp reflection from approximately 15 ft away for a brief moment and then proceeded to blend into the road surface. Making the same run with the polarized lens, the vivid dark oil spot was again clearly visible from a much longer distance and for a longer period of time.This same test was performed with the speeds increased up to 50 mph and the sun moving high up into the noon sky.Summary:The ability to see oil or fluid in the road surface has several contributing factors:a. Direction rider is traveling vs. time of day position of the suni. The higher the sun got, the harder it became to see the puddle with out the polarized lensb. Distance from the oil puddlei. The riders were consistently able to see the oil from further away regardless of position to the sun with the polarized lensc. Speedi. As speeds increased it became increasingly difficult to see the oil unless the riders were looking for the vivid dark puddle with the polarized lensLooking for a sharp reflection vs. the vivid dark puddle seen through the polarized lens
# We were consistently able to spot the vivid dark puddle on every pass with the polarized lens regardless of direction of travel to the sun. The sharp reflection with out the polarized lens only became apparent when we were traveling at the right angle from the sun and became increasingly difficult to see with increasing speeds.Although probably not the most scientific of experiments, it was clear that once the rider became familiar with what to look for– the dark oil puddle vs. the sharp reflection — he/she could consistently see the oil from further away, from different directions and at higher speeds with the polarized lens than with out it.After several years of using polarized lenses for road racing motorcycles, including multiple US Regional and National Championships, our conclusion is that not only is there a real benefit gained from the technology, but an actual advantage to the wearer.