Our eyes perceive the color of objects differently under different lighting conditions, which stems from differences in brightness and color perception. The eye is a complex regulator that detects contrast, color, distance, and depth, and adjusts the amount of light to suit the environment.
The color of an object seen under electric light or special lighting may appear different when viewed again in natural light. This is because our eyes’ ability to perceive color is very different in the dark than in the light. In particular, the distortion of an object’s color under artificial light is due to the fact that the human eye perceives colors differently depending on the temperature or spectrum of the light. For example, an object may appear warmer under incandescent light, while it may appear cooler under fluorescent light. In this way, the human eye needs light to see objects. In addition to distinguishing between contrast and color, the eyes can also tell far and near, and create a sense of depth. They can also adjust the amount of light that enters the eye depending on the brightness of the environment, and they have the ability to adjust from seeing close objects to seeing far away objects.
The human eye is about 2.3 centimeters in diameter, shaped like a ball with a convex bulge at the front and is elastic. The outermost part of the eye is lined with a white sclera and inside is a black choroid, which allows light to enter only through the pupil. At the front of the eye is the transparent cornea, through which light passes and is refracted and focused by the lens-shaped crystalline lens inside the eye, which forms an image on the retina. This retina contains the optic nerve cells that receive light impulses. The retina is also located at the back of the eye and is made up of a thin layer. This retina is actually one of the most important parts of the eye, as it’s responsible for converting light impulses into electrical signals that are transmitted to the brain. Damage to the retina during this process can lead to poor vision or even blindness, which is why retinal health is so important.
These optic nerve cells are made up of two types: cone cells, which are cone-shaped, and rod cells, which are rod-shaped and also called interstitial cells. Cone cells are concentrated in a narrow area near the focal point of the retina, and their number is very small compared to rod cells. Rod cells, on the other hand, are distributed throughout the entire retina and are much more numerous than cones. Cones and rods are sensitive to different colors of light, with cones being most sensitive to light with a wavelength around 500 nanometers (yellow) and rods being most sensitive to light with a wavelength around 560 nanometers (green). The distribution and function of these two types of cells allows us to see in both bright daylight and darkness.
Because cone cells are fewer in number, our eyes are much less able to perceive colors in the dark, but they work well in bright light, with light near yellow (the red-orange-yellow range) being particularly noticeable. This is why we use yellow or red to indicate a warning or danger. These colors are highly visible in bright light and are effective for safety, but they can also be useless when it gets dark. For example, safety signs and traffic lights on the road use this principle to increase visibility, often using yellow and red colors. However, these can be less effective in the evening or at night, so additional lighting or reflective materials are used to maintain visibility.
The human eye has evolved to be sensitive to the most common visible light around us, which means it would have evolved to be sensitive to yellow light, which is the most common and strongest light around us, so it seems natural that we are most sensitive to yellow. However, the majority of the cells in the optic nerve are rod cells, which are able to detect light thanks to a substance called rhodopsin, which is derived from vitamin A. When rhodopsin is broken down by light, it stimulates the optic nerve, and this stimulus is transmitted to the cerebrum, where it is used to perceive objects. Although these cells do not perceive color, they are more sensitive to green light, meaning that green objects are easier to see in the dark, even though they do not perceive color.
This is probably related to the green color of plants: our eyes may have evolved to better identify plants that are both a source of food and shelter for humans. This may explain why green is perceived as a relaxing and soothing color. However, in order to quickly identify dangerous conditions, it would have become necessary to detect danger using yellow light, which is stronger than green light. In other words, the human eye uses a small number of cone cells to detect danger and a large number of rod cells to identify prey. This shows that the human eye has evolved to adapt to different environments that are relevant to survival.
