Comparison of Tear Evaporation Rate With DAILIES TOTAL1 and Biotrue ONEday

Comparison of Tear Evaporation Rate With DAILIES TOTAL1 and Biotrue ONEday

The purpose of this pilot study is to compare the effect of DAILIES TOTAL1, a low water content silicone hydrogel lens, and Biotrue ONEday, a high water content hydrogel lens, on the rate of tear evaporation. The study will also serve to validate the novel, in-house developed evaporimeter.

Inclusion Criteria:

1. Is at least 17 years of age and has full legal capacity to volunteer;
2. Has read and signed an information consent letter;
3. Is willing and able to follow instructions and maintain the appointment schedule;
4. Has worn soft contact lenses for a minimum of 6 months;
5. Currently wears soft contact lenses for at least 4 days per week and 8 hours per day;
6. Has an acceptable fit and comfort with both study contact lenses in the powers available;
7. Has less than or equal to 1.00DS difference between eyes in their habitual contact lenses;
8. Is willing to be awake for at least 2 hours before visit 2;
9. Is willing to not wear eye makeup on the day of visit 2 and 3;
10. Is willing to not use eye drops or artificial tears on the day of visits 1, 2, and 3;
11. Has a wearable pair of spectacles.

Exclusion Criteria:

1. Is participating in any concurrent clinical or research study;
2. Has any known active* ocular disease and/or infection;
3. Has a systemic condition that in the opinion of the investigator may affect a study outcome variable;
4. Is using any systemic or topical medications that in the opinion of the investigator may affect a study outcome variable;
5. Has known sensitivity to sodium fluorescein dye;
6. Is pregnant, lactating or planning a pregnancy at the time of enrolment (by verbal confirmation at the screening visit);
7. Is aphakic;
8. Has undergone refractive error surgery;
9. Has a known sensitivity to petroleum jelly (Vaseline);
10. Has epilepsy and/or a sensitivity to flashing lights;
11. Wears toric contact lenses;
12. Has any physical impairment that would interfere with holding the evaporimeter;
13. Has taken part in another research study within the last 14 days.