Purpose

• Ten to 20 percent of people are affected by dry eye. Over-the-counter eye drops like GenTeal and Systane are used to decrease the dry, gritty irritation of dry eye.
  
  

Composition

• Systane consists of polyethylene glycol 400 0.4 percent (lubricant), propylene glycol 0.3 percent (lubricant), hydroxypropyl guar and polyquaternium-1 as a preservative. GenTeal is composed of 0.3 percent hydroxypropylmethyl cellulose with GenAqua (sodium perborate) as a preservative
  
  

Preservatives

• The preservatives used in both drugs are considered acceptable by the University of Illinois. Polyquaternium-1 and sodium perbonate are less damaging to the eye surface than more commonly used preservatives.
  
  

Lubricants

• Hydrogels increase viscosity and keep tears on the eye longer. The hydrogel in GenTeal is hydroxypropylmethyl cellulose (HPMC). Systane uses two hydrogels, hydroxypropyl-guar, which creates a stronger tear film rather than replacing it, and propylene glycol.
  
  

Making a Choice

• The choice of eye drop is an individual one. Both drops contain preservatives not considered harmful to the eye, and both contain hydrogels. Trying both drops to see which works best for you is a reasonable option.