Central Corneal Swelling With Silicone Hydrogel Materials

Inclusion Criteria: 1. The participant must be at leat 18 years old or older and no greater than 65 years old. Children younger than18 will likely no be able to come back and forth to the clinic during the typical work week as outlined in the above (due to school schedules) and thus not be able to adhere to the protocol. 2. The participant must be a current soft contact lens wearer who routinely wears lenses at least 6-8 hours per day and at least 4 days per week for at least the past 3 months. 3. Refraction suitable for spherical soft contact lens powers between -1.00 and -6.00 D the participant must be correctable to 20/30 or better at distance with both eyes with dispensed contact lenses. 4. The participant must be free of any active anterior segment disorders that would preclude safe contact lens wear. Active anterior segment disorders and evidence of central microbial keratitis are not allowed. However, evidence of past CLPU will be allowed so long as no more than 3 such scars are detected bilaterally. Evidence of more than 3 CLPU-like scars places excessive risk on the participant for subsequent CIE. 5. The participant must be correctable to 20/25 or better in each eye with spectacles. Amblyopia will be excluded. 6. Flat and steep corneal curvatures from keratometry readings must be between 39.00 and 48.50 D, respectively. Corneal curvatures outside this range may be indicative of a disease state, and the participants are not expected to comfortably wear the study lenses. 7. The participant must own or agree to purchase a pair of spectacles that can be worn when lenses are removed, during the washout periods, or in case of ocular discomfort or emergency. Exclusion Criteria: 1. The participant has worn rigid gas permeable contact lenses within the last 30 days or PMMA lenses within the past 12 months. These lenses can transiently alter the corneal shape and influence the fitting of soft contact lenses or alter endothelial cell morphology. 2. The participant has an immunocompromising disease or any other systemic disease that in the investigator's opinion will affect ocular health or increase risk during daily contact lens wear. 3. The participant is taking any medication that in the investigator's opinion will affect ocular physiology or study participation. 4. The participant has an ocular disease or condition such as aphakia, clinically significant corneal dystrophies, corneal edema, external ocular infection, iritis, or had any anterior segment surgery. 5. The participant is taking any ocular medications. If a participant was previous taking any ocular medications, the medications must have been discontinued at least 2 weeks prior to enrollment. 6. The participant must have less than or equal to grade 2 on any of the slit lamp observations of: upper tarsal papilla, corneal staining, corneal neovascularization, conjunctival injection, and lid erythema or scales. 7. The participant is currently pregnant or lactating. Participant who become pregnant during the study will be discontinued. 8. An employee or member of the UHCMC Eye Institute or a family member of any study personnel.