Healthy Young Adults, Accommodation Disorder
Conditions
Brief summary
This clinical study aims to understand how glasses with a small reading addition affect the way the eyes focus and work together in young adults with normal near vision. Some people experience focusing difficulties or visual discomfort during near-vision activities such as reading or using digital devices. This study will evaluate whether glasses with a small reading addition can help reduce these difficulties and improve visual comfort. Researchers will compare two different pairs of glasses designed to provide additional support for near vision. They will assess how each pair affects eye focusing and eye coordination using standard optometric examinations. Participants will: * Wear three pairs of glasses, each for approximately 4 weeks. * Complete eye examinations to evaluate focusing ability and eye coordination. * Answer questionnaires about visual comfort, eye strain, and overall quality of vision.
Interventions
DEVICEEye exam
An optometric eye exam
OTHERQuestionnaires
Questionnaires on the eye fatigue and the quality of vision
DEVICEWashout lenses
Standard single-vision spectacle lenses prescribed according to each participant's refractive error and worn during the washout period before allocation to the study lenses.
DEVICEReference lenses
Spectacles lenses optimized near vision lenses for the comparator
DEVICETest lenses
Spectacles lenses optimized near vision lenses for the test
Sponsors
Essilor International
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
SUPPORTIVE_CARE
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* 1.Voluntary person, fluent in English willing to follow the protocol, able to read and understand the information form and give his free and informed consent * 2.Aged between 18 and 35 years old * 3.Non-presbyopic * 4.Wears glasses for at least 6 hours per day * 5.Distance refractive error (Sphere) within the range of \[-6.00D to +3.00D\] (with cylinder in the negative form) * 6.Cylindrical component of the refractive error within the range of \[0 to -2 D\] in both eyes * 7.Anisometropia within the range of \[0.00D to +1.50D\] * 8.A visual acuity with new prescription at distance and at near greater or equal to 20/25 (6/7.5, 0.1 logMAR) monocularly and binocularly * 9.No visual acuity difference inferior or equal to 0.1 logMAR between right and left eye at distance and at near * 10.Phakic eyes * 11.Daily activities of the participant mostly in near vision (at least 6 hours during weekday)
Exclusion criteria
* 1.Pregnant woman or nursing * 2.Persons deprived of their liberty by a judicial or administrative decision and persons hospitalized without consent and persons admitted to a health or social institution for purposes other than research * 3.Adults who are unwilling or unable to express consent * 4.Participant in exclusion period from another study * 5.Persons wearing or that have previously worn any type of anti-fatigue or lenses with a boost * 6.Persons who don't wear glasses * 7.Severe ocular pathology declared, involving a loss of visual field as in glaucoma or involving a loss of acuity and strong discomfort in environments with little or too much light as in retinitis pigmentosa or moderate or severe dry eye diagnosed. * 8.Reported neurological deficit, including a history of epilepsy or sensorimotor coordination disorders, vestibular or cerebellar pathology (e.g., balance disorders, dizziness) * 9.Overt aphakic or pseudophakic (intraocular implant) * 10.Constant or intermittent diplopia or double vision with a +1.00D lens at near * 11.Ocular diseases nor general pathologies with an impact on visual field or vision. * 12.Reported systemic condition, medical treatment or medication that affects vision * 13.Manifest or decompensating latent strabismus, amblyopia, nystagmus. * 14.Known contraindication to cyclopentolate 1% or its excipients * 15.Known risk of angle-closure glaucoma.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Accommodative facility difference | From enrollement to the end of the participation at about 16 weeks | Measurement of the accommodative facility to understand the flexibility of the accommodation. It will be measured in cycle per minute (cpm) using a +/-2.00D flipper lens test at 40cm according to standard clinical accommodative facility testing procedures. Lenses are placed in front of the eyes to stimulated or not the accommodation on a text. The main goal of the participant is to keep clear and single the target while switching between the accommodative lenses and the non accommodative lenses. The results obtained after the wearing period of each lenses will be compared together. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Visual fatigue questionnaire score | From enrollement to the end of the participation at about 16 weeks | Visual fatigue assessed using a validated questionnaire, CISS (Borsting et al, Optometry and Vision Science. 2003, 80(12):832-838). Total questionnaire scores (range 0 to 56 with a higher score meaning a higher fatigue) obtained after each lens-wear period will be compared between the reference lens and the test lens |
| Visual Comfort Questionnaire Score | From enrollement to the end of the participation at about 16 weeks | Visual comfort assessed using a questionnaire administered at the end of each lens-wear period. Questionnaire scores (range from 0 to 182) will be compared between the reference lens and the test lens. |
| Vision Quality Questionnaire Score | From enrollement to the end of the participation at about 16 weeks | Subjective quality of vision assessed using a questionnaire. Total questionnaire scores (range from 0 t o182) will be compared between the reference lens and the test lens. |
| Participant Lens Preference | From enrollement to the end of the participation at about 16 weeks | Participant preference for the reference lens or the test lens assessed at the completion of both lens-wear periods using a preference questionnaire. |
| Near Phoria | From enrollement to the end of the participation at about 16 weeks | Near phoria (in prismatic diopter) measured using standard clinical procedures. Phoria values obtained after participants wore the reference lens and the test lens will be compared. |
| Sheard Criterion | From enrollement to the end of the participation at about 16 weeks | Sheard criterion calculated from measurements of phoria and fusional vergence reserves. Values obtained after participants wore the reference lens and the test lens will be compared. |
| Vergence Capacity | From enrollement to the end of the participation at about 16 weeks | Vergence capacity assessed using fusional vergence measurements (in prismatic diopter) obtained under standard clinical conditions. Results after participants wore the reference lens and the test lens will be compared. |
| Maximum Comfortable Convex And Concave Lens Power | From enrollement to the end of the participation at about 16 weeks | Maximum convex or concave lens power (in diopter) that can be comfortably accepted while maintaining clear binocular vision. Values obtained after participants wore the reference lens and the small-power lens will be compared. |
| Accommodative Lag | From enrollement to the end of the participation at about 16 weeks | Accommodative lag measured in diopters during a near-vision task using an objective method of accommodation assessment. Values obtained after participants wore the reference lens and the test lens will be compared. |
| Day effect on Accommodative Lag | From enrollement to the end of the participation at about 16 weeks | Difference in diopter between morning and evening accommodative lag measurements. |
| Diurnal change in refraction | From enrollement to the end of the participation at about 16 weeks | Difference between morning and evening refraction measurements. Diurnal changes will be compared between the reference lens and the small-power lens conditions. |
| Day effect on near phoria | From enrollement to the end of the participation at about 16 weeks | Difference between morning and evening measurements of near phoria (in prismatic diopter). Diurnal changes will be compared between the reference lens and the small-power lens conditions. |
| Day effect on Sheard Criterion | From enrollement to the end of the participation at about 16 weeks | Difference between morning and evening Sheard criterion values. Diurnal changes will be compared between the reference lens and the small-power lens conditions. |
| Day effect on AC/A ratio | From enrollement to the end of the participation at about 16 weeks | Difference between morning and evening accommodative convergence to accommodation (AC/A) ratio measurements. Diurnal changes will be compared between the reference lens and the small-power lens conditions. |
| Diurnal change in Fusional Vergence Reserves | From enrollement to the end of the participation at about 16 weeks | Difference in prismatic diopter between morning and evening fusional vergence reserve measurements. Diurnal changes will be compared between the reference lens and the small-power lens conditions. |
| Diurnal Change in Binocular Accommodative Facility | From enrollement to the end of the participation at about 16 weeks | Difference between morning and evening binocular accommodative facility measurements expressed in cycles per minute. Diurnal changes will be compared between the reference lens and the small-power lens conditions. |
| Diurnal Change in Monocular Accommodative Facility | From enrollement to the end of the participation at about 16 weeks | Difference between morning and evening monocular accommodative facility measurements expressed in cycles per minute. Diurnal changes will be compared between the reference lens and the small-power lens conditions. |
| Association Between Lens Satisfaction and Refractive Measures | From enrollment to the end of the participation at about 16 weeks | Association between participant satisfaction scores, cycloplegic refraction measurements, and subjective refraction measurements evaluated at the end of the study. |
Countries
United Kingdom
Contacts
CONTACTMiriam Conway, PhD
Outcome results
None listed