Assessment of Three Basic Progressive Lens Designs

Not Applicable

Completed

Interventions: Device: Progressive Additional Lenses (PAL), pre calibrated and made of polymeric material with anti-reflection coating

Brief Summary: This clinical trial investigates the differences between three different progressive addition lens designs. It is a non-invasive double-masked randomized clinical investigation. For this study, 80 participants will be recruited.

Detailed Description: The purpose of the study is to evaluate the preference, adaptability, and visual performance of three progressive lens designs. The difference in these lens designs is a variation of zone sizes for intermediate and near vision. The clinical trial helps manufacturers and eye care practitioners to give detailed suggestions to patients. Study participants will be experienced progressive addition lens wearers, which will be recruited by advertisements, by email, and with direct person-to-person solicitation. The study will be conducted at the Eye Care Institute at the Patient Care Center Western University of Health Sciences, Pomona, CA, 91766. For each participant, the study is completed in around two months and requires three separate visits.

Recruitment & Eligibility

Inclusion Criteria

Age: 45 to 70 years old.
Visual Acuity: far & near monocular: cc ≥ 20/20 (decimal cc ≥ 1.0)
Normal binocular vision (at distance & near: no strabismus on cover testing, aligning prism of less than 2Δ horizontally or vertically, stereoacuity of 2' or better at distance and near).
Prescription is in the range:
- Spherical power: less than +/-6.00 D
- Cylindrical power: less than -2.75 D
- Addition: 1.50 D - 2.50 D
- Difference in power (spherical equivalent) between eyes: less than 2.00 D

Exclusion Criteria

Have never worn any progressive lens design.
First prescription for progressive lenses.
Prescription found during visit#1 varies from current prescription more than 0.50 D in any meridian.
Currently wearing single vision lenses with accommodative support.
Double vision or prismatic prescription in current glasses.
Known ocular disease including strabismus, any pathology, any eye surgeries that may affect visual acuity.
Use of systemic or ocular medications that are likely to affect vision.
Balance problem/vertigo problem.
Concurrent participation in other vision-related research.

Arm && Interventions

Group	Intervention	Description
The other PAL design wearers	Progressive Additional Lenses (PAL), pre calibrated and made of polymeric material with anti-reflection coating	Subjects who have been already wearing any from the other design type of PAL
Experimental: The specified PAL design wearers	Progressive Additional Lenses (PAL), pre calibrated and made of polymeric material with anti-reflection coating	Subjects who have been already wearing any from specified design type of PAL

Primary Outcome Measures

Name	Time	Method
Evaluate the Adaptation to Progressive Lens Designs.	Entire study duration (approx. 4 weeks)	Evaluate the adaptation to progressive lens designs through a "Satisfaction questionnaire" after 1 week of use of each of the 3 progressive addition lenses. Scale titles: Visual Quality Scale: A 5-point scale from a minimum value of 1 to a maximum score of 5. Higher scores mean better outcomes.

Secondary Outcome Measures

Name	Time	Method
Evaluate the Immediate Preference Among Progressive Lens Designs.	Directly after receiving the lenses (approx. 15 minutes)	Evaluate the immediate preference for progressive lens designs through a "Satisfaction questionnaire" directly after receiving the 3 progressive addition lenses. Scale titles: Visual Quality Scale: A 5-point scale from a minimum value of 1 to a maximum score of 5. Higher scores mean better outcomes.
Evaluate the Preference of Progressive Lens Designs.	Entire study duration (approx. 4 weeks)	Evaluate the final preference of progressive lens designs after wearing each of the 3 PALs for one week. Scale title: Preference of Progressive Addition Lenses Scale: "Pair 1", "Pair 2, "Pair 3"