This pilot study will investigate the impact of sterile saline drops that are formulated at hypo-osmolar levels on CL comfort in comparison to an iso-osmolar drop, in a group of symptomatic CL wearers.

Inclusion Criteria:

• Is at least 17 years of age;

• Has full legal capacity to volunteer;

• Has read and signed an information consent letter;

• Is willing and able to follow instructions and maintain the appointment schedule;

• Is willing and able to stay within the School of Optometry and Vision Science building for the duration of each Study Day;

• Currently wears daily, soft, frequent replacement lenses licensed in Canada (daily, bi-weekly or monthly disposable lenses, no extended wear, no monovision) for at least 3 days/week and 6 hours/day during the 2 months prior to enrolment;

• Is symptomatic according to the following classification:

  • Reports a difference between average and comfortable wear time with habitual lenses of at least 3 hours;
  • Fall into the symptomatic group as per Young's criteria (Appendix 4).

• Is able to remove and insert the lenses by themselves;

• Owns a wearable pair of spectacles;

• Is willing to wear the study lenses for 10 hours;

• Has visual acuity (VA) correctable to logMAR 0.20 or better in each eye;

• Shows an acceptable lens fit with their habitual lenses;

Exclusion Criteria:

• Is participating in any concurrent clinical or research study;
• Has any known active* ocular disease and/ or infection;
• Has any ocular abnormality that would contraindicate contact lens wear;
• Has any known infection or inflammation that requires treatment or has a systemic condition that in the opinion of the investigator may affect the study measures;
• Is using any systemic or topical medications that in the option of the investigator may affect the study measures;
• Has any known sensitivity to the diagnostic pharmaceuticals and products to be used in this study;
• Is pregnant or lactating (by verbal communication) due to potential ocular physiology changes that may affect the study outcome;
• Is aphakic;
• Has undergone refractive error surgery;
• Is a member of the CCLR directly involved in the data collection. *For the purpose of this study, active ocular disease is defined as an infection or inflammation that requires therapeutic treatment. Mild (i.e. not considered clinically relevant) lid abnormalities (blepharitis, meibomian gland dysfunction, papillae), corneal and conjunctival staining and dry eye are not considered an active ocular disease. Neovascularization and corneal scars are the result of previous hypoxia, infection or inflammation and are therefore not active.