The AA has issued an alert warning motorists to choose sunglasses carefully as they could be be hit with heavy fines. The association released a bulletin before the start of the sunny bank holiday weekend last Friday.
The advisory said choosing sunglasses which did not let in enough light and then driving could result in a fine as high as £2,500. Sunglasses are rated in five categories, zero to four. The AA and outdoor sports equipment suppliers such as Ultralight Outdoor Gear say Category Four sunglasses should not be worn when driving.
Category Four lenses are designed to protect against UV and visible light and allow in less than one tenth of any natural light. They are too dark for normal driving and should just be worn for specific activities in locations with bright sunlight.
The UK's National Eyecare Trust has compiled a list of recommendations for people buying sunglasses to drive and these emphasise the AA's. The trust notes that buyers should ensure prospective purchases carry the CE/BS EN 1836:2005 seal of approval.
The trust also says sunglasses with lenses in blue or pink should be avoided and ones with anti-reflective finishes are best at reducing the glare from bright sunlight. A final piece of advice which is obvious to most, but not all, drivers is that sunglasses are unsuitable for night-driving or when it is raining, cloudy or snowy.
Despite the warning over too dark sunglasses, drivers could land up in hot water for not wearing any at all. The Highway Code stipulates that drivers who are dazzled in overbright sunlight need to reduce speed or pull off the road immediately. Sunglasses would more than likely be effective in these situations.