According to this study, you can get dry eye or allergic blepharitis from eyelash extensions. A key culprit is formaldehyde in the glues. - There is just no free lunch with eyelash enhancements, is there? Even Latisse has dry eye (among other things) as a side effect.

Ocular disorders due to eyelash extensions.

PURPOSE:
: Eyelash extensions are a beauty treatment in which individual synthetic extensions are applied, lash by lash, to natural eyelashes. The procedure is becoming popular worldwide because they seem more natural and last longer than other types of false eyelashes. However, partly because a bonding agent (glue) containing organic substances is applied near the eyes, consultations with ophthalmologic clinics and the National Consumer Affairs Center of Japan have increased annually. In the present study, we investigated eye disorders due to eyelash extensions.

METHODS:
: Ocular disorders were retrospectively investigated in 107 women (age 21-52 years) who visited ophthalmologic clinics in Japan with complaints of eye symptoms resulting from eyelash extensions between March 2007 and March 2010. The patients had no history of eye diseases. Of the patients 42 were 21 to 29 years of age, 44 were 30 to 39 years, 19 were 40 to 49 years, and 2 were 50 to 60 years. Three glues, the ingredients of which are not disclosed, were chemically analyzed for detection of more than 70 substances suspected to be ingredients.

RESULTS:
: The ocular disorders due to eyelash extensions included keratoconjunctivitis due to invasion of glue or removing agents in 64 patients, allergic blepharitis due to glues in 42 patients (4 of these patients developed both keratoconjunctivitis and allergic blepharitis), conjunctival erosion due to eyelid-fixing tapes in 3 patients, allergic blepharitis due to eyelid-fixing tapes in 1 patient, and subconjunctival hemorrhage due to compression during removal of extensions in 1 patient. In all 107 patients, the symptoms were resolved by adequate treatments with eye drops and/or ointments. Ingredient analysis detected formaldehyde in concentrations above the standard threshold level in all 3 glues. In addition, lead and benzoic acid were also detected; however, concentrations of these particular compounds were low and therefore unlikely to cause disorders in humans.

CONCLUSIONS:
: Eyelash extension procedures may cause ocular disorders, such as keratoconjunctivitis and allergic blepharitis; indeed, all glues for eyelash extensions analyzed in the present study contained formaldehyde, which can cause keratoconjunctivitis. From the viewpoint of hygienics, it is necessary to disinfect devices, provide handling instructions for organic solvents, improve glue ingredients, and improve the ophthalmologic knowledge of the practitioners.
Cornea. 2012 Feb;31(2):121-5.
Amano Y, Sugimoto Y, Sugita M.
From the *Department of Ophthalmology, The University of Tokyo, Graduate School of Medicine, Tokyo, Japan; †Department of Social Medicine, Toho University School of Medicine, Tokyo, Japan; and ‡Eikokai Medical Foundation, Nakameguro Eye Hospital, Tokyo, Japan.