These strips work by staining the cornea blue upon instillation. This causes ?speckling? of the cornea, which gives the ophthalmologist immediate indication of any dry patches, as well as ay muco-deficient or damaged corneal cells. Most importantly, I does not sting the eye like Rose Bengal, and either of the white or blue light of the sli lamp can be used during examination. Available as sterile strips in individual peel-open pouches.Lissamine Green Strips box of 100 strips set of 6 boxes