A scotopic curve is a graphical representation of the sensitivity of the human eye to light under low-light conditions, such as at night or in very dimly lit environments.
- The scotopic curve resembles a line graph that shows how sensitive the human eye is to light in these low-light conditions. It is an important tool for understanding night vision. The curve illustrates the minimum amount of light needed for the eye to detect different wavelengths (colours) of light.
- This information is derived from the response of our rod cells, which are more active in low light compared to the cone cells that dominate in bright conditions.
- Closely related to the scotopic curve is the photopic curve, which represents the sensitivity of the human eye to different wavelengths of light under well-lit conditions. While the scotopic curve peaks at around 498 nanometers (blue-green light), indicating that our eyes are most sensitive to these wavelengths in low light, the photopic curve peaks at around 555 nanometers (green-yellow light) under bright conditions.
- It is interesting to note that the scotopic and photopic curves use different units to measure light. The scotopic curve uses units related to light intensity per unit area (such as brightness per square degree), whereas the photopic curve uses units similar to overall brightness.