How can prismatic effect at the NVP be minimised?
Answer: By designing the lens so that the opitcal centre of the near segment overlies the NVP of the main lens exactly so that the segment contribute no additional prism above that of the main lens.
How can prismatic effect at the NVP be minimised?
Answer: By designing the lens so that the opitcal centre of the near segment overlies the NVP of the main lens exactly so that the segment contribute no additional prism above that of the main lens.