"The ideal artificial lubricant should be preservative free; contain potassium, bicarbonate, and other electrolytes; and have a polymeric system to increase its retention time."*
Modern tear substitutes are entirely free of preservatives.
Phosphates can have a bad influence:
Eye drops that are used in dry eyes, particularly after eye surgery or injuries should not contain phosphate buffers.
CandorVision – Your eyes are everything!
©2013 CandorVision (a division of Candorpharm Inc.)
CP 23073 Montreal, Canada, H4A 1T0