Changes in lighting conditions throughout the day can significantly affect glare, eye comfort and subsequently, visual perception. Similar to needing different shoes for different activities, comfort and surface conditions(e.g. running, hiking, water activities), your eyes need different lenses for each of the different lighting conditions, for the ultimate in UV and screen protection, comfort from glare to optimize vision. As a result, the selection of two lenses (e.g. Lx1 for indoor, screen use and Lx3 for outdoor sun), may be an ideal combination. Please see Lx Lens Guide to best find the 1-2 pairs that meet your needs.