None listed
Conditions
Brief summary
This study aims to find out how varying eye prescription impacts on vision and satisfaction of vision. To achieve this, we wish to monitor participants' eyes’ responses to the changes to their prescription we introduce. A minimum of 20 people will take part in this study. At each visit, a pre-determined number of changes to their prescription will be shown to the participant through a phoropter (standard optometric equipment used to determine spectacle prescriptions), they will then be asked to read a letter chart and rate their vision clarity and satisfaction.
Interventions
Participants will attend a baseline visit at the Brien Holden Vision Institute, where a qualified optometrist will measure their best-corrected subjective refraction (required sphere power and required cylinder power) using a phoropter.
Following the baseline, participants will attend 4 separate visits on different days at the Brien Holden Vision Institute. Each visit will take approximately 30 minutes.
At each of these visits, participants will undergo pre-determined changes to their cylindri
Participants will attend a baseline visit at the Brien Holden Vision Institute, where a qualified optometrist will measure their best-corrected subjective refraction (required sphere power and required cylinder power) using a phoropter. Following the baseline, participants will attend 4 separate visits on different days at the Brien Holden Vision Institute. Each visit will take approximately 30 minutes. At each of these visits, participants will undergo pre-determined changes to their cylindrical axis and power in a randomised fashion using a phoropter, by a qualified optometrist. Visual acuity (taken with an electronic letter chart at 6 metres) and subjective vision response (clarity, vision satisfaction using a 1-10 numeric scale) will be obtained for each change. A different cylinder power is assessed at each visit: (1) the required cylinder power, (2) the required cylinder power minus 0.25 D, (3) the required cylinder power minus 0.50 D or (4) the required cylinder power minus 0.75 D. The order of these powers is randomised. Within each visit, the following cylindrical axes will be tested in a randomised fashion: aligned, misaligned by +10 degrees, +20 degrees, +30 degrees, -10 degrees, -20 degrees, -30 degrees. In summary, at each of the four visits, participants will be shown 7 different views of a letter chart, and vison and subjective response will be measured for each view. The washout period between each cylindrical axis will be approximately 5 minutes. The washout period between each cylindrical power will be at least one night.
Sponsors
Brien Holden Vision Institute
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
-Able to read and comprehend English and give informed consent as demonstrated by signing a record of informed consent. -Be at least 18 years old, male or female. -Have at least 0.75D cylindrical power in at least one eye. -Willing to comply with the clinical trial visit schedule as directed by the Investigator. -Have ocular health findings considered to be “normal” and which would not prevent the participant from giving accurate visual acuity data.
Exclusion criteria
-Any pre-existing ocular irritation, injury or condition (including infection or disease) of the cornea, conjunctiva or eyelids that would affect visual acuity measurements. -Any systemic disease that adversely affects ocular health e.g. diabetes, Graves disease, and auto-immune diseases such as ankylosing spondylitis, multiple sclerosis, Sjogrens syndrome and systemic lupus erythematosus. Conditions such as systemic hypertension and arthritis do not automatically exclude prospective participants. -Use of or a need for concurrent category S3 and above ocular medication at enrolment and/or during the clinical trial. -Use of or a need for any systemic medication or topical medications which may alter normal ocular findings / are known to affect a participant’s ocular health / physiology or visual acuity either in an adverse or beneficial manner at enrolment and/or during the clinical trial. -Eye surgery within 12 weeks immediately prior to enrolment for this trial. -Rigid gas permeable (RGP) or Orthokeratology lens wear within previous 12 months -Previous corneal refractive surgery. -Currently enrolled in another clinical trial. -Pregnancy.
Outcome results
None listed