Assessment of the Relationship of Soft Contact Lens Fit and Power (Fit & Lens pOwer Soft lenSes)

NCT06745375 | Enrolling By Invitation

• 1 other identifier: HLS21201
• Study Type: interventional
• Target: 38
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is to evaluate whether altering the optical power (in dioptres) of a contact lens affects both vision and lens fit. As the majority of modern contact lens wearers prefer daily disposable soft lenses, the trial lenses used in this study-provided by CooperVision-reflect this trend, representing nearly 80% of the current UK market. This study aims to generate data supporting the use of contact lenses with powers that do not precisely match a participant's visual prescription (within ±2.00 dioptres) as a viable temporary alternative when the exact required power is unavailable. At present, there is no published literature in the context of modern contact lens design that compares the fitting characteristics of 'fit-for-purpose' lenses with those of lenses from the same design family that would not typically be selected due to power mismatch.

Conditions

Healthy Participants Study; Contact Lens Wear; Contact Lens Fit

Keywords

contact lens; contact lens wear; contact lens fit

Outcome Measures

Primary Outcomes (3)

• Soft contact lens movement: Subjective and objective assessment of soft contact lens movement.

  Lens movements will be graded between 0.25 - 0.50 mm = Optimum, \<0.25 = Less movement; \>0.50mm is more movement.

  within 30 mins of lens wear

• Soft contact lens horizontal lag:Subjective and objective assessment of soft contact lens lag.

  Lens lag will be graded as: \<50% lag = less leg, 50% to 100% is optimum lag, \>100% = high lag.

  within 30 mins of lens wear

• Soft contact lens tightness: graded subjectively as optimum, loose and tight

  Soft contac tlens tightness

  within 30 mins of lens wear

Secondary Outcomes (1)

• Assessment of ocular comfort with soft contact lenses

  within 30 mins of lens wear

Study Arms (1)

Healthy participants

EXPERIMENTAL

All healthy participants wear two different contact lenses, one with the correct power and one with +/- 2.00 Ds to actual refraction. All lenses are commercially available. No 2nd arm.

Device: contact lens wear

Interventions

contact lens wear DEVICE

participants wear two different powered contact lenses (one with actual power, and one +/- 2.00Ds) contact lenses. No 2nd arm

Healthy participants

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Between 18-60 years of age
• Vision correctable to at least 6/12 (20/40) or better in each eye
• with mental capacity to provide written consent in English (as per the Mental Capacity Act, 2005).
• happy to wear investigational contact lenses

You may not qualify if:

• Any active infection or inflammation, history of major systemic or ophthalmic conditions
• use of systemic or topical medications known to affect the eye in the previous 3 months
• history of ocular surgery, currently enrolled on another study/clinical trial that may impact outcome
• any other contraindications for typical contact lens wear
• As per the Mental Capacity Act, 2005, participants will be automatically excluded if not deemed to have Capacity for consent or under the age of 18.

Sponsors & Collaborators

• Aston University: lead
• CooperVision, Inc.: collaborator

Study Sites (1)

School of Optometry, Aston Eye Clinic

Birmingham, UK, B4 7ET, United Kingdom

Location

MeSH Terms

Interventions

Contact Lenses, Extended-Wear

Intervention Hierarchy (Ancestors)

Contact Lenses, Hydrophilic; Contact Lenses; Lenses; Optical Devices; Equipment and Supplies

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: OTHER
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: This crossover study compares patients' actual prescription contact lenses with lenses ±2.00 dioptres to assess differences in fit. Key fitting metrics include lens movement (\<1.00 mm), coverage, and push-up tests. Using G\*Power (v3.1.9.4), a sample size of 38 was calculated. The study uses paired assessments (same participant wears both lenses) to evaluate lens movement in mm. Literature reports mean ± SD of 0.352 ± 0.355 mm and 0.269 ± 0.179 mm, with high correlation (r = 0.95) (Belda-Salmerón et al.). A clinically significant difference is set at 0.25 mm. To achieve 80% power with a 5% Type I error and accounting for a 10% dropout rate, 38 participants are required.

Study Record Dates

• First Submitted: December 9, 2024
• First Posted: December 20, 2024
• Study Start: January 30, 2026
• Primary Completion (Estimated): August 31, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: January 21, 2026

Record last verified: 2026-01

Locations

GB (1)