Colorblindness, also known as color vision deficiency, is the decreased ability to see color or differences between colors. It affects around 1 in 12 men and 1 in 200 women globally. While colorblindness cannot be fully cured, there are ways to improve color perception and make distinguishing colors easier.
What is colorblindness?
Colorblindness occurs when there is an abnormality in the color-sensing cones in the retina at the back of the eye. There are three types of cones that each sense a different wavelength of light that our brains interpret as red, green or blue. When one or more of these cones malfunction, the brain receives abnormal signals about color.
The most common types of colorblindness are:
- Red-green color blindness – where the red or green cones don’t work properly. This makes it hard to distinguish between reds, greens, browns and oranges.
- Blue-yellow color blindness – where the blue cones don’t work properly. This makes it hard to distinguish between blues and yellows.
- Total color blindness (achromatopsia) – where none of the cone cells work properly. This means the person can only see in black, white and shades of grey.
Colorblindness is usually inherited genetically and affects men more than women. Red-green color blindness is the most prevalent, affecting about 1 in 12 men and 1 in 200 women of Northern European descent.
What causes colorblindness?
In most cases, colorblindness is caused by inherited faulty genes on the X chromosome that produce abnormal photopigments in the cone cells. As the X chromosome carries photopigment genes, men only need one copy of the faulty gene to be colorblind but women need two copies. This is why it is much more common in men.
The most common cause is a genetic mutation in the OPN1LW or OPN1MW genes that make the photopigments for red and green cones. Other causes include:
- Mutations in the OPN1SW gene affecting blue cones
- Damage to the retina or optic nerve from disease, injury or medications
- Aging
- Certain eye conditions like cataracts
- Drinking alcohol during pregnancy
- Lead or mercury poisoning
In rare cases, colorblindness is acquired later in life due to disease or damage rather than inherited genetically.
How is colorblindness diagnosed?
Colorblindness is normally first noticed in childhood when learning colors. Typical symptoms include:
- Difficulty identifying and distinguishing between colors like reds, greens, oranges, browns, purples and grays
- Needing very bright colors to detect differences
- Confusing similar hues like red and green, pink and gray, orange and brown
- Having a limited range of colors seen
- Difficulty identifying colored objects or choosing matching colors
To diagnose colorblindness, eye care professionals use tests like:
- Ishihara color test – identifying colored numbers within dot patterns
- Farnsworth D-15 test – arranging color caps in hue order
- Hardy-Rand-Rittler (HRR) plates – finding colored symbols in colored dot patterns
- Anomaloscope – matching red/green or blue/yellow light mixes
These allow testing of each eye separately to determine the type and severity of color vision deficiencies. More extensive testing can identify the specific faulty photopigment genes.
How to improve color perception
While there is currently no complete cure for inherited colorblindness, there are ways to improve color perception and ability to differentiate colors, including:
Colorblind glasses
Special colorblindness correction glasses filter and enhance colors to increase contrast between similar hues like red/green and blue/yellow. This enhances the wearer’s ability to differentiate between colors. Brands like EnChroma, Pilestone and Oxy-Iso have lenses optimized to improve color perception for different types of color vision deficiencies.
Colorblind apps
Apps like Chroma, See Color and Coblis can help people with colorblindness by converting images on mobile devices into alternate color schemes to improve color differentiation. Many include simulations so those with normal color vision can understand how people with deficiencies see.
Daily habits
Simple daily habits can help manage colorblindness:
- Use bright, contrasting colors that are easy to differentiate
- Label colors
- Buy clothing with clear labels for color
- Get others’ input when color coordinating outfits
- Use a color identifier app or colorimeter device to scan and identify colors
Occupational aids
People with color vision deficiencies can use aids in occupations where color differentiation is important:
- Lighting that gives better color rendering
- Digital devices that name or indicate colors
- Labels or color codes for colored wires, charts, etc
- Workplace support and awareness from managers
- Avoiding occupations where vital color distinctions are required for safety
Medical treatments
While there is currently no complete cure, research is underway into medical treatments to restore normal color vision by replacing or repairing malfunctioning cone cells, including:
- Gene therapy – Delivering normal genes into cone cells to restore function
- Stem cell therapy – Transplanting stem cell-derived functioning photoreceptors
- Optogenetics – Introducing light-sensitive proteins into remaining cone cells
- Nanoparticle therapy – Using nanoparticles to convert light into electrical signals
- Retinal prosthesis – Implanting a computer chip to stimulate optic nerve signaling
While promising, most of these are still in the research stage with limited human trials so far. But they offer future hope for restoring color vision.
Outlook for correcting colorblindness
The prognosis for correcting color perception depends on the individual’s specific color vision deficiency. While complete cures are not yet available, future medical research offers hope. In the meantime:
- Glasses and apps can help enhance colors for many with red-green deficiencies
- Daily habits and occupational aids allow managing most everyday challenges
- Genetic screening helps identify likelihood of passing on inherited colorblindness
- Support, understanding and awareness from family, friends, employers and educators is important
Inherited colorblindness may not be curable yet, but new assistive technologies and potential future medical treatments provide optimism that correcting color perception is on the horizon.
Conclusion
Colorblindness affects a significant proportion of people worldwide. While there is presently no complete cure, improving technology offers several ways to enhance color perception and make daily functioning easier. Medical research continues to progress on treatments to repair malfunctioning cone cells and restore normal color vision. The future looks hopeful that science will one day find a way to correct various types of color vision deficiencies.
