If your operators are protected from eye hazards while in the cab I'd dispense with the need for eye protection while driving. Alternatively choose eye protection with a flatter lens or speak to manufacturers about a gradual tint lens which reduces glare in daylight but provides clear vision when moving from dark to light. They also look pretty cool. Our fork truck and crane drivers use them without problem.

Lee, I introduced safety shades a few years ago. There were some concerns then on a similar note and I admit I didn't use the most expensive brands.

I had the same culture to overcome so used a 'sun safe' campaign and simply opted for 'mirror shades' version of specs - cool! I devised a simple Q&A which had a signature (guess what for) and a 'prize' of a pair of shades for correct answers. Needless to say I dished out more than 1 pair each but mission accomplished.

I now use wraparound safety specs myself for various activities - such as skiing and motorcycling, and buy a box at a time for personal consumption (about 10% the cost of 'sportswear' versions but made by the same mfctrs for those interested :<)).

I can say that some brands (but not all and not necessarily linked to price) certainly do give distortion, especially on peripheral vision / lens bottom and can induce a slight headache /nausea if worn for long periods.

My advice is to try them (properly) before introducing a new range.

Steve