UK CAA definition of "normal fields of vision"
EASA MED.B.070 (e) states that “Applicants for a Class 1 medical certificate shall be required to have normal fields of vision and normal binocular function”. For the purpose of clarity the UK CAA defines "normal fields of vision" as follows:-
Monocularly, on Esterman field testing, there should be no more than a single missed spot within 20 degrees vertically from the primary position and 30 degrees horizontally from the primary position. There should be no confluent area of missed spots outside this area.
Additionally, binocularly, on Esterman field testing there should be no more than 4 missed spots, of which not more than 2 shall be contiguous in the visual field defined horizontally by 60 degrees either side of the primary position and vertically by 20 degrees above the primary position and 30 degrees below the primary position.
Normal binocular function is defined as any individual with a degree of binocular lock. This would include individuals with normal binocular single vision and those individuals with well-adapted heterotropias, who are not at risk of diplopia and have adopted a suppression scotoma when both eyes are open.