Abstract: Benzyldimethyl {2-[2-(p-1,1,3,3-tetramethylbutylphenoxy)ethoxy]ethyl} ammonium chloride (BDT) forms the basis of contact lens solutions that are unusually effective at reducing the number and wide variety of pathogenic microorganisms that may infect rigid gas permeable or soft contact lenses. Furthermore, it has been discovered that natural occurring compounds alone and in combination with chemical agents can be used in ophthalmic solutions such as contact lens solution to enhance and complement their anti-microbial, cleaning and wetting activity or to reduce irritation to the eye. The basic contact lens solution comprises an effective concentration of BDT (preferably 1 to 100 parts per million), with naturally occurring plant products possessing activities complementary to BDT, in an isotonic diluent buffered with a physiologically acceptable buffer to a physiologically natural range.