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Why Are So Many Men Color-blind?

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Color blindness is known to be more common in males. That comes down to the genetics of the condition.Credit: Dima Berlin via Getty Images

An estimated 300 million people worldwide are color-blind. This typically means they can't distinguish certain shades of color, they struggle to tell how bright colors are or, more rarely, they can't see any colors at all. Color blindness doesn't affect males and females equally, though. According to Cleveland Clinic, the condition affects about 1 in 12 males, compared with 1 in 200 females.

So why are so many more males color-blind than females?

The answer comes down to the genetics governing the function of the human eye. People see colors using specialized cells in the backs of their eyeballs called cones. There are three types of cone cells, and each is tuned to be most sensitive to certain wavelengths of light.

"There are three types of cones that see color: red, green and blue," Dr. Usiwoma Abugo, a clinical spokesperson for the American Academy of Ophthalmology, told Live Science in an email. "When one or more of these color cone cells are absent or not working properly, color blindness happens."

The most common form of color blindness is red-green color blindness. This happens when people are born without the type of cones that are attuned to red and/or green light, or when those cones are in short supply or are inadvertently tuned to the wrong wavelength of light.

If a person has problems with the blue-sensitive cones in their eyes, they will be blue-yellow color-blind, although this form of color blindness is less common than red-green. And if every type of cone is missing or substantially impaired, it can cause total color blindness, also called "complete color vision deficiency." But this form of color blindness is extremely rare, affecting fewer than 1 in 30,000 individuals.

Related: New cells discovered in eye could help restore vision, scientists say

Color blindness affects males more often than females because it's typically caused by a recessive genetic trait linked to the X chromosome.

Recessive traits typically aren't expressed unless a person inherits two dysfunctional copies of a gene, meaning one copy from each parent. As such, a person with one functional copy of a cone-cell gene will usually have normal color vision.

Most males carry one X and one Y chromosome in each cell; they inherit their single X chromosome from their mother and their Y from their father. The genes responsible for the light-sensitive proteins that constitute cone cells are located solely on the X chromosome, though, so that means males get one only copy of each gene — and just one chance for each to work properly.

Thus, if that lone copy has a mutation, they'll likely be color-blind. Females, on the other hand, typically have two X chromosomes in each cell — one from each parent. So even if one X chromosome carries a faulty version of a cone-cell gene, the other often carries a working copy that can compensate. As a result, females are much less likely to develop color blindness, although they can still carry and pass on the faulty genes that underpin the condition.

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"Women can experience color blindness, but it's quite rare and is usually caused by something other than genetics," Abugo said. Conditions such as inflammation of the optic nerve, cataracts and glaucoma can cause color blindness later in life, for example.

For now, there aren't any widely available cures for color blindness, but some researchers are investigating experimental gene therapies that could give people with visual deficits tied to their genetics the chance to see the world in full color.

In these animal experiments and early trials with humans, scientists use a harmless virus to deliver functional cone genes into the eyes. These therapies have so far been used to restore full color vision in animal models with the same genetic mutations that color-blind people have, and now, they're now being investigated in humans.

This article is for informational purposes only and is not meant to offer medical advice.

Colour Blindness: All You Need To Know About People Who Can't See Colours

Here's an overview covering its causes, treatment options, and prevention:

Causes

Genetics: The most common cause of color blindness is genetics. It usually occurs due to an inherited defect in the X chromosome affecting the photopigments in the retina. Men are more commonly affected because they have only one X chromosome, whereas women have two.

Disease: Some diseases that affect the retina or optic nerve, such as glaucoma, macular degeneration, diabetes, multiple sclerosis, Alzheimer's disease, and Parkinson's disease, can lead to color vision deficiencies.

Chemicals and medications: Exposure to certain chemicals like fertilizers and solvents, as well as medications such as some antibiotics, anti-tuberculosis drugs, and high doses of aspirin, can induce color vision problems.

Aging: The ability to see colors can diminish as part of the natural aging process.

Treatment

No cure for genetic causes: There is currently no cure for genetically inherited color blindness. However, certain tools and aids can help manage the condition:

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Color filters: Special glasses and contact lenses with filters can enhance color perception for some people.

Apps and Software: Many digital solutions can modify on-screen colors to make them more distinguishable for color-blind users.

2. Addressing underlying conditions: For color blindness caused by underlying health conditions, treating the disease may improve color vision. Regular medical checkups to monitor and manage these conditions are important.

Prevention

Preventing color blindness is not usually possible, especially for genetic forms. However, taking general precautions to protect eye health can be beneficial:

Avoid exposure to harmful chemicals that might affect vision.

Manage chronic diseases effectively under medical guidance to minimize their impact on vision.

Regular eye examinations can help in early detection and management of potential problems that could influence color vision.

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Managing color blindness effectively often involves utilizing various aids and adapting environments to accommodate the visual limitations of those affected. Here's an outline of common management strategies for color blindness:

Adaptive devices and technology

Color-corrective glasses and contacts: These lenses can help enhance color discrimination and are especially useful in environments where color identification is crucial, such as driving or identifying traffic lights. Brands like EnChroma and Colorlite offer glasses designed specifically for color vision deficiencies.

Screen modifications: Computers and mobile devices can be adjusted to better suit the needs of color-blind users. Operating systems and websites often feature accessibility settings that include color filters or modes tailored to different types of color vision deficiencies.

Special apps: Numerous apps are available that help color-blind individuals identify colors through their mobile devices. These apps use the camera to analyze and name colors in real time.

Understanding color blindness and adapting to it involves educational resources and supportive technologies, which can significantly improve the quality of life for those affected.

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A Golden Opportunity: Using Gold Contacts To Correct Color Blindness

Golden Eye

ACCESS Health International

This story is part of a series on the current progression in Regenerative Medicine. This piece is part of a series dedicated to the eye and improvements in restoring vision.

In 1999, I defined regenerative medicine as the collection of interventions that restore tissues and organs damaged by disease, injured by trauma, or worn by time to normal function. I include a full spectrum of chemical, gene, and protein-based medicines, cell-based therapies, and biomechanical interventions that achieve that goal.

Color is an integral part of our daily lives, from the vibrant hues of nature to the vivid visuals of art and media. However, not everyone can fully appreciate the spectrum of colors surrounding us. Color blindness, also known as color vision deficiency (CVD), affects millions worldwide, hindering their ability to distinguish between specific colors.

It is a condition where individuals have difficulty distinguishing between specific colors. This occurs due to a genetic mutation that affects the proteins responsible for detecting color in the retina's cone cells. CVD can affect the range of activities and occupations that patients can engage in and can limit their ability to perform specific tasks that involve color differentiation.

Fortunately, modern technology offers a solution in the form of color-correcting contact lenses, with gold contacts being a promising new development that offers hope for those seeking a more natural and effective treatment.

Tinted Lenses To Correct Color Vision Deficiency

Tinted glass lenses are a wearable device that can help manage CVD difficulties. They are also the most commonly used corrective device for color deficiencies. The lenses work by selectively filtering out specific wavelengths of light, enhancing color contrast, and improving perception. By doing so, the lenses enable individuals to distinguish between previously indistinguishable colors.

One well-known company that provides tinted glasses for CVD is Enchroma. While these lenses are effective, they are not a permanent solution. Additionally, they can be inconvenient since they must be worn regularly to maintain effectiveness. Despite these limitations, tinted glasses remain a popular option for individuals with CVD who want to improve their color perception.

Contact Lenses for Color Blindness

Recent technological advances have led to the use of contact lenses that incorporate special filters. These filters selectively block specific wavelengths of light, enhancing the ability of individuals with CVD to differentiate between colors. The filters can be customized to each individual's needs, allowing for a more personalized approach to correcting CVD.

Compared to tinted glasses, contact lenses are more comfortable and less obtrusive. They provide a more natural viewing experience since they sit directly on the eye rather than in front of it. Additionally, contact lenses can be worn during sports or other physical activities where glasses might be less practical.

However, not all contacts are created equal regarding CVD treatment, and one novel type is gaining popularity over the others.

A New Golden Standard of CVD Treatment?

Gold is highly suitable for making contact lenses because it is biocompatible and has excellent optical properties. Researchers have used these properties to create gold nanocomposite contact lenses that incorporate gold nanoparticles into the contact lens matrix. These gold nanoparticles are engineered to selectively filter out specific wavelengths of light, which can help improve color differentiation and perception in individuals with color vision deficiency (CVD).

A recent study was published in ACS Nano to investigate the efficacy of these gold nanocomposite contact lenses in treating CVD. The study recruited participants with CVD to wear gold contact lenses and complete various color-related tasks. The study showed that the gold contact lenses significantly improved color discrimination in individuals with mild to moderate CVD. Furthermore, the contact lenses were well-tolerated and did not produce any adverse effects.

(a) transmission spectra of the nanocomposites; (b) solutions before polymerization (scale: 10 mm); (c) steps in polymerizing the solutions and obtaining the lenses; (d) polymerized lenses at different nanoparticle concentrations (scale: 10 mm).

Copyright © 2021 American Chemical Society

While the results of this study are promising, some limitations need to be addressed. Firstly, the study's sample size was relatively small. Therefore, further research with a larger sample size is necessary to ensure the effectiveness of gold contacts. Additionally, the study only focused on individuals with mild to moderate CVD, and it remains to be seen if these contacts will be effective in individuals with severe CVD.

Despite these limitations, gold nanocomposite contact lenses represent an exciting development in CVD correction. With further research and development, these lenses could provide a more natural and permanent solution for color blindness.

The Future is Here and In Color

Furthermore, this research opens the possibility of developing other nanocomposite materials to correct visual impairments. For example, these materials could create contact lenses that correct visual acuity or sharpness. The potential applications of nanocomposite materials in the field of ophthalmology are vast and exciting, and it will be fascinating to see how the area develops in the future.

To learn more about the eye, read more stories at www.Williamhaseltine.Com

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