[1] Dry eye syndrome (keratoconjunctivitis sicca) is a common ocular surface disorder and is characterized by disruption of the tear film and increased inflammation.

[3] The mucous layer contains mucins, gelatinous glycoproteins, which allow for an even distribution of the tear film over the corneal surface and decreased friction during blinking.

[8] Preservatives include benzalkonium chloride (BAK),[8] ethylenediaminetetraacetic acid (EDTA),[8] purite,[8] chlorobutanol,[9] sodium perborate,[9] thiomersal,[9] disodium edetate,[9] and oxychloro complex (SOC).

[9] For instance, high concentrations of benzalkonium chloride (BAK) can cause cytotoxicity, cause cell lysis, and reduce tear and mucin production.

[12] Risk factors for developing dry eyes includes increasing age, female gender, environments with low moisture, nutritional deficiencies, certain medications, and autoimmune conditions.

They are composed of many components including enzymes that act as natural antibiotics, proteins that prevent bacterial growth, and nutrients.

[10] Thicker artificial tears that come in the form of gel or ointments may be used in more severe cases as they last longer, although they may temporarily blur vision.

[17] Prescription drops may have additional side effects such as burning, redness, pain, and a foreign body sensation.

[19] Artificial tears are a part of the topical therapy for keratoconjunctivitis sicca for animals such as dogs, cats and horses.

[21] A veterinarian should be contacted if any signs of allergy, irritation, or pain develop due to the usage of artificial tears.

[21] A 2016 Cochrane Review seeking to compare the effectiveness of various over the counter artificial tears in treating dry eye.