What Part of the Eye Allows You to See Color?

The Physics of Light and Color
Sir Isaac Newton, renowned for his law of universal gravitation, also investigated the nature of light. As early as 1672, Newton learned that white light can be divided into an orderly spectrum of colors by bending that light through a prism. Each color occurs as a specific wavelength of electromagnetic radiation. Every object reflects certain wavelengths of light and absorbs others. You perceive the differences in these reflected light waves as color. You are capable of distinguishing millions of different colors thanks to the cones of your retinas — each of which, in fact, is sensitive to one of only three colors.

The Cones
Cones are present throughout the retina, but they are packed together most densely in the central area of the retina, which is called the fovea. Cones contain molecules called photopigments that absorb light and change shape, setting off a change in electrical state that is transmitted to the brain. Each cone contains one of three different versions of these photopigments, making it sensitive only to red, green or blue wavelengths. The interaction of the information transmitted by the eye’s cones and the brain creates the colors you see.

Color Sensitivity
Each human eye contains about six million cones. The quantity you have of each type of cone and the quality of their functionality affect your ability to see subtle color variations. However, the brain relies also on comparisons between the input from different cones and between an object and the other parts of the image you are seeing. Researchers such as neurobiologist Semir Zeki, for example, study the regions of the brain specifically concerned with color constancy, that is, the ability of the brain to recognize and discount temporary lighting conditions that affect a color’s appearance in order to maintain a constant perception of color. Without this constancy, color would be useless as a means of identifying things.

Color Blindness
Seven percent of American males suffer from varying degrees of color blindness, which is an inability to differentiate red from green. This trait originates during initial exchanges of genetic material once egg and sperm meet. Jeremy Nathans, a Howard Hughes Medical Institute investigator working at Johns Hopkins University School of Medicine, has found that the genes that create red and green color receptors are located near each other. Their DNA sequences differ by only 2 percent, making exchanges that result in absent or malfunctioning red or green cones more likely to occur. Only 0.4 percent of women are colorblind because women receive two copies of the X chromosome, which carries the genes for these two receptors. This reduces their odds of ending up with only defective versions of the genes. Blue color blindness is extremely rare; it is only caused by gene mutation.

10 Foods To Improve Your Eyesight Naturally

Have you ever wondered if there was a way to reduce the risk of vision loss, or improve your eyesight naturally without an expensive medical procedure? Apparently there is, and it’s as simple as eating some of the right foods. Now, these aren’t some rare, exotic plants or food extracts, and they aren’t foods that will cost you a fortune either. These foods are obtainable at your local grocery, and can be infused into your regular diet and meal preparation with ease. Take a few minutes to go over this list of 10 foods that can help improve your eyesight naturally:

1.Garlic: Used in numerous dishes to enhance flavors and aromas, garlic has been shown to have numerous benefits for your health. It can help enhance the flow of blood, bolster the immune system, and it is good for your eyesight. Garlic is rich in sulfur, a nutrient that helps the body produce antioxidants that can protect the lens of the eye.

2.Eggs: Among the foods that are beneficial to your eyes, eggs are one of the most common. Eggs, and egg yolks in particular, carry an abundance of nutrients that are beneficial to your eyes and the rest of your body. Typically, the darker the egg yolk, the more nutritious it is.

3.Salmon: Vitamins A and D, and probably the most important, omega 3 fatty acids are all present in salmon. These healthy components of this delicious fish promote improved eyesight by boosting your brain power.

4.Leafy green vegetables: Broccoli, spinach, kale – if it’s green and has leaves, it is a vegetable that is beneficial to improved eyesight. With an abundance of nutrients like vitamin A, vitamin B12, vitamin C and calcium, it’s hard to pass up the addition of these vegetables to your daily diet. According to the Glaucoma Research Foundation, spinach, in particular, is loaded with antioxidants like lutein and zeaxanthin, which are typically found in your eyes. If you want to gain the most benefits from these vegetables, try not to overcook them. You don’t want to cook out all of those nutrients.

5.Dark chocolate: As if you needed an excuse to eat this rich, decadent treat, dark chocolate has been shown to be very beneficial to your eyesight. By adding dark chocolate to your diet, you are increasing your intake of flavonoids that help protect blood vessels in your eyes. By protecting the blood vessels in your eyes, you are strengthening your eye lens and cornea as you age and your eyes begin to weaken.

6.Bilberries: Studies have shown that the consumption of bilberries can lead to the reversal of eye disorders like macular degeneration, which is the loss of vision in the center of a person’s visual field, and typically occurs in older adults.

7.Avocados: Like spinach, avocados are rich in antioxidants commonly found in the eye like lutein and zeaxanthin. Avocados are said to contain more lutein than any other fruit, which is important for improving your eyesight since lutein has the ability to reduce the risk of macular degeneration and cataracts.

8.Carrots: The most common food associated with improved eyesight is carrots. Carrots, and many other yellow and orange vegetables and fruits, contain beta-carotene, which is said to be good for the retina and can help protect your eyes from damage caused by the sun.

9.Wine: Similar to dark chocolate, wine, especially red wine, contains flavonoids that are good for blood vessels and blood circulation, which is beneficial to your eyes. This doesn’t mean you should go on a crazy wine bender. Moderation is the key to utilizing the health benefits of wine.

10.Soy: Provide more nutrition to your eyes with soy. This food is low in fat, high in protein, and it contains important fatty acids and other nutrients that are beneficial to your eyes.

Take advantage of this list of foods to improve your eyesight naturally. Don’t wait till it’s too late, and you need expensive procedures or vision correction to have functioning eyesight. These foods won’t cost as much money as something like laser eye surgery, and they are quite tasty. Aside from foods to help improve your eyesight naturally, you should also avoid or cut back on the following foods as much as possible to prevent vision loss.

Color Blindness

Color blindness occurs when there is a problem with the color-sensing granules (pigments) in certain nerve cells of the eye. These cells are called cones. They are found in the retina, the light-sensitive layer of tissue that lines the back of the eye.

If just one pigment is missing, you may have trouble telling the difference between red and green. This is the most common type of color blindness. If a different pigment is missing, you may have trouble seeing blue-yellow colors. People with blue-yellow color blindness usually have problems identifying reds and greens, too.

The most severe form of color blindness is achromatopsia. A person with this rare condition cannot see any color, so they see everything in shades of gray. Achromatopsia is often associated with lazy eye, nystagmus (small, jerky eye movements), severe light sensitivity, and extremely poor vision.

Most color blindness is due to a genetic problem. (See: X-linked recessive) About 1 in 10 men have some form of color blindness. Very few women are color blind.

The drug hydroxychloroquine (Plaquenil) can also cause color blindness. It is used to treat rheumatoid arthritis, among other conditions.

Interesting Eye Facts

*Your eyes are composed of more than 2 million working parts.

*We all have microscopic creatures lurking in our eyelashes.

*The average person blinks 12 times per minute – about 10,000 blinks on an average day.

*Color blindness is more common in males, about 1 in 10 have some form. In the most common type of color blindness, individuals have trouble telling the difference between red and green.

*Only 1/6 of your eye is exposed to the outside world. It is 2.5 cm in length and weighs about 7 grams.

*The muscles that move the eye are the strongest relative to their size in the body.

*Your eyes begin to develop 2 weeks after conception.

*Your eyelashes act like windshields to catch dust and debris before they reach your eyeball.

*At birth your eyes are about 70% of their adult size, but your ears and nose never stop growing.

*The entire length of all the eyelashes shed by a human in their life is over 98 feet.

*The older we are the less tears we produce.

*When you blink, you shut your eyes for 0.3 seconds. That’s a total of 30 minutes each day!