The Effect On Visual Function By Fresnel Prisms
Research type
Research Study
Full title
The effect on visual acuity and contrast sensitivity by Fresnel prisms with the alteration of gaze angle and prism strength
IRAS ID
271055
Contact name
Patrick Keating
Contact email
Sponsor organisation
The University Of Sheffield
Duration of Study in the UK
0 years, 10 months, 26 days
Research summary
Title: The effect on visual function by Fresnel prisms
Why is the study being done?
This experiment will be investigating how Fresnel prisms affect visual acuity and contrast sensitivity. Fresnel prisms are used within the Orthoptic clinic to correct and alleviate double vision. Visual acuity is a measure of a level of your vision (how well you can see) and contrast sensitivity is the ability to differentiate targets of different shades. The study will be comparing how Fresnel prisms of different strengths and how varying the angle in which the prism is looked through impacts vision and contrast sensitivity.
By taking part in the experiment data will be used to show how vision function is affected as prism strength is increased. This will give clinicians more information on which to decide the type of prism prescribed within the eye clinic in giving the best visual outcome.
What will be done? / Where will the study take place?
The experiment will involve wearing different range of glasses with a prism placed on one lens, the participant will be asked to read the smallest letter visible on a vision and contrast sensitivity chart. An adjustable chin rest will be used to change head position and thus the angle looking through the prisms. The study will take approximately 30 minutes and will take place in the Orthoptic clinic at Lincoln County Hospital. In order to participate in the study good visual acuity will be required (0.00 LogMAR or 20/20 vision) and no history of strabismus (misaligned eyes) or any binocular vision problems. The study will not be conducted on patients in the hospital but on NHS staff members who meet the inclusion criteria.
REC name
N/A
REC reference
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