4. Apply the eye... if y-e-s spells yes, what does e-y-e-s spell? The eye is a very useful tool in our lives, in fact the eyes are a great pair! In our investigations along with riveting video content we have been developing an idea of power and brightness (intensity). This assignment has asked you to consider how these things relate to apertures. In the eye we have a variable aperture called the pupil. Your eye adjusts the size of this aperture in response to the light in your environment. Based on your understanding of power and brightness of light, do you think your eye is responding to the power or brightness of the light when changing your pupil size? Does a shrinking pupil reduce the brightness of the light entering your eye? Discuss.