FIELD OF VISION Flashcards
Explain field of vision
The entire area that can be seen when looking forward; including both the central and peripheral vision
Factors affecting the size and shape of visual field
- anatomy of the eye
- age
- eye conditions
- pathology
- refractive error
- environmental factors
Apparent field of view
Refers to the field of view obtained by an empty aperture frame subtending the eyes centre of rotation
Real field of view
Refers to the actual field of view obtained subtended by the effective diameter of the lens, conjugate with the eyes centre of rotation
Compare field of view for hyperopic and myopic wearers
Myopic patients will always have a larger field of view then a hyperopic patient.
Advice to hyperope to improve field of view
Larger frame choice, ideally the BCD matches the patients PD
Advice to myope to improve field of view
Consider lens/ frame shape. Round or oval frame reduces visual distortions at edges to increase/ improve FOV
Factors affecting field of view
- vertex distance
- prescription type
- power
- reduced aperture
