What is the angle subtended by the topmost letter in the Snellen's chart at the Nodal point of the eye when the person seeing it at 6m from the chart?
5 min
10 min
40 min
50 min
The topmost letter subtends 5 min at Nodal point of the eye when viewed from 60 m.
So the same letter subtends 50 min at Nodal point of the eye when viewed from 6 m (By cross multiplication).