Clinical trial NCT02821403: Effects of Blue-light Blocking Lens on Visual Functions
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Effects of Blue-light Blocking Lens on Visual Functions
Lead sponsor: The Hong Kong Polytechnic University
Sponsor class: OTHER
First posted: 2016-07-01
Enrollment: 80
Sex: ALL
Minimum age (years): 18
Maximum age (years): 55
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: OTHER

Brief summary: Working Hypothesis: The blue-light blocking lens has no effect on the contrast sensitivity, accommodative response, color vision, and subjective grading of the quality of life and vision.

Purpose: To determine and compare the visual performances after wearing the blue-light blocking lenses in participants with and without presbyopia.

Methods: One hundred and sixty computer users (computer usage \>2 hours/day) with (n=120, aged \>40years) and without presbyopia (n=40, aged 18-35 years) will be recruited. Three pairs of ophthalmic lenses will be prescribed for the participants, in which one pair of them will be the blue-light blocking lenses (StressFree, Swisscoat, HK). The lenses will be used for intermediate vision (i.e., computer usage) in presbyopic group, and for distant vision in non-presbyopic group. The adaptation period for each pair of lenses will be 1 month. The pre- and post-treatment contrast sensitivity, accommodative response and color vision will be measured. The participants will also be asked to complete questionnaires about their quality of life and vision, and the performances of these ophthalmic lenses.

Significance: The blue-light blocking lens reflects the short-wavelength lights and protects the retina from "blue-light hazards"; however, blue lights are essential for various visual function and circadian rhythms. This study will evaluate the impact of the blue-light blocking lenses on visual function and quality of life, and determine whether the blue-light blocking lenses are good choices for extra ocular protection.


Eligibility criteria: Inclusion Criteria:

* age: 18 to 35 years OR 40 to 55 years
* daily computer usage over over 2 hours per day

Exclusion Criteria:

* visual acuity worst than 0 logMAR
* abnormal binocular and color vision
* previous history of ocular surgeries

Primary outcomes:
measure: Contrast Sensitivity as Assessed by Mars Contrast Sensitivity Chart
timeFrame: Every 1-month interval from the date of randomization, up to 3 months
measure: Color Vision as Assessed by the Farnsworth Munsell 100 Hue Test
timeFrame: Every 1-month interval from the date of randomization, up to 3 months
Secondary outcomes:
measure: Self-assessment of Lens Performance Through Questionnaire
timeFrame: Every 1-month interval from the date of randomization, up to 3 months
Other outcomes:
Locations:
Study officials:
References:
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