Measures glare without leaving the refracting lane. Three variable light intensity settings simulate glare conditions. Evaluates tinted lenses, sunglasses and anti-reflectives to quantify improvement in glare disorders. Macular photo stress testing. The new BAT "HEAD" is manufacturered with twist-lock mechanism that easily attaches to most standard rechargeable 3.5V well handles. No more custom handle and recharging base. This means it will slip right into most instrument stand wells, or after-market desk top welll chargers.