Have you ever wondered what the world looks like through your dog’s eyes? Can he appreciate the vibrant hues of a sunset like we do? The answer lies in a fascinating twist in biology, where a single small molecule offers humans a much more colorful world.
How do cats and dogs see colors?
Cats and dogs perceive colors differently than humans due to variations in their retinal structure and the distribution of photoreceptor cells. While humans have three types of cone cells sensitive to different wavelengths of light, allowing us to see a broad spectrum of colors, cats and dogs have fewer cone cells. Dogs only have two types of cones, making their color vision similar to that of a red-green colorblind human.
This means that they primarily perceive the world in shades of yellow and blue, without having the ability to effectively distinguish between red and green hues. In contrast, cats have slightly more sophisticated color vision than dogs, but still limited compared to humans. Like dogs, cats have two types of cone cells, which means they also have dichromatic vision. However, recent studies suggest that cats might be a little more sensitive to colors in the blue-violet range.
A tiny cell that changes a lot of things
In a recent study, researchers from Johns Hopkins University and the University of Washington took a closer look at differences in color vision in humans and pets. And according to the results of the study published in the journal PLOS Biologya derivation of vitamin A generates specialized cells that allow humans to see millions of colors, an ability that dogs, cats and other mammals do not possess.
To reach this conclusion, the researchers cultivated human retinal organoids in the laboratory. They exposed the retinas to retinoic acid – a natural derivative of vitamin A – early in the cultured cells’ development. This resulted in higher ratios of green cones in the organoid after 200 days. It was also observed that immature cones from organoids exposed to low levels of retinoic acid later developed into red cones.
It was concluded that the retinoic acid molecule determines whether a cone will specialize in detecting red or green light. Note that for decades, scientists thought that red cones formed through a random selection mechanism in which cells randomly committed to detecting green or red wavelengths. But this study provides a whole new understanding of this phenomenon, but also of vision disorders that affect color perception such as color blindness. Furthermore, this test will allow you to evaluate your perception of colors.
