Final answer:
Option (B), The Purkinje Effect is the shift from photopic to scotopic vision as we move from brightly lit to darker environments, transitioning from cone to rod dominance in our eyes.
Step-by-step explanation:
The shift in sensitivity from photopic to scotopic vision is called the Purkinje Effect. This phenomenon occurs as we move from a brightly lit environment to a darker one, causing our vision to switch from cone-dominated (photopic) to rod-dominated (scotopic). The cones, which are responsible for our color vision and operate well under bright light, become less effective in low light.
Conversely, the rods, which are more sensitive and contribute to our night vision, become more active allowing us to see in dim light. This transition can take some time, which is why we may initially have difficulty seeing when entering a dark environment.