Suppose of light energy is needed by the interior of the human eye to see an object

PHYSICS · Subjective · CBSE · Physics · Dual Nature of Radiation and Matter · Dual Nature of Radiation and Matter

Problem

Suppose

10^{-17} \text{ J}

of light energy is needed by the interior of the human eye to see an object. How many photons of green light (

\lambda = 550 \text{ nm}

) are needed to generate this minimum amount of energy?