Do you have cataract? It is a disease of old age. Most times, cataract affects an individual due to exposure to radiation, chemicals and other environmental factors that reduce the ability of the eyes to function properly. Cataract, as a disease, is due to the lens that captures light in the eyes becoming opaque, thereby preventing light from passing through to the photoreceptor cells at the retina.
I wrote an article this week on the dress that caused a sensation on social media circles because of the difficulty it imposes on a viewer as to light perception. Persons who suffer visual problems like cataract do not enjoy and revel in the sensation of light and color as others. French impressionist, Claude Monet, is in that class. Her visual problems made her paintings imprecise and muted in colors. If you suffer from visual problems, you have to cope with inefficient light reception.
Is it white and gold, or blue and black?Credit: User swiked on www.tumblr.com
Apart from the cones and the rods in the retina which distinguishes daylight from night vision, there is another group of cells in front of the retina which work towards our enjoying color.
Those cells are called Müller cells or müller glia. These cells function as light and color filters. Their position in front of the retina makes sure that the light getting to the rods and cones are already sorted, filtered and organized. Clever, not so?
Müller cells, according to Dr Erez Ribak from Technion, the Israel Institute of Technology, are at just the “the right height, and their light-bearing trunks are just the right width, to filter the wavelengths correctly”.
So, as you look at the dress again, and if you wonder why so many persons disagree on what color they perceive, you could place the müller cells as one of the candidates at the heart of their visual problems, if not a disease like cataract.
The brain perceives color when light falls on the retina and interprets these colors by sending the light, as electrochemical signals, to the brain. The rods perceive night vision while the cones at the retina perceive color.
It’s not so simple as that because vision involves more than just perceiving darkness and color. It includes, as this BrainHQ.com article describes it, distilling foreground from background, recognizing objects in various orientations and accurately interpreting spatial cues.
A dress was recently posted on tumblr.com (click to see it yourself), the social networking site, and the question was: what is the color of the dress? Is it white and gold, or blue and black?
The question brings up the concept of how the brain interprets color. At least, the following factors determine how your brain interprets colors so you do not go about thinking you must have an eye problem.
Time of the day, whether during the day, when the cones are at work, or the night, when the rods are more at work.
Surrounding light conditions or illumination.
Distance between the eyes and the object or dress, in this case.
Medium of perception: air, monitor, cellphone screen or TV screen.
Stored memory of past experiences and interpretations.
You can find these explained on abcnews.go.com.
Actually, the dress is not white and gold, but shades of black and blue. The brain at work tweaks colors in varied ways that no color stays true throughout the day.
