Cat® sunglasses are precision-engineered to be tough and durable without compromising on style. And now, through an exclusive collaboration with EnChroma, these select frames feature EnChroma's latest lens technology which can enhance colour vision for approximately 80% of people with red-green colour blindness.

Developed to increase the contrast between the colour signals, alleviating symptoms of colour blindness for a richer experience of the world. Colour blindness can cause each person to see colour differently, colour blindness glasses are designed to improve the colour vision of people with forms of red-green colour blindness, they are not intended to assist the vision of people with blue-yellow colour deficiency.

What is Normal Colour Vision?

When light enters the eye, it activates millions of photoreceptor cone cells that can normally detect all the colours of the rainbow. The three types of cone cells, which send signals to your brain, are sensitive to different parts of the visible colour spectrum and are generally referred to as blue, green and red cones.

• A person with normal colour vision can typically perceive up to 1 million different shades of colours.
• Normal colour-sighted individuals are Trichromats, meaning that they have three different colour sensitive cones in their retina: red, green, and blue.
• Each of these red, blue, and green cones are sensitive to different wavelengths of light and help to create colour perception.
• The unique separation and overlap work together to enable those with normal colour vision to see all the colours of the spectrum.
• It is believed that a person with typical red-green colour blindness often perceives only 10% as many shades of colour as a person with normal colour vision.

What is Colour Blindness?

Most types of colour blindness occur when there is an excessive overlap of the green and red colour cones in the eye, causing distinct hues to become indistinguishable. As a result, those with colour blindness only see a fraction of the millions of hues and shades of colours seen by those with normal colour vision.

Colour blindness or colour vision deficiency (CVD) includes a wide range of causes and conditions and is actually quite complex. It's a condition characterized by an inability or difficulty in perceiving and differentiating certain colours due to abnormalities in the three colour-sensing pigments of the cones in the retina. Each cone is responsible for processing different wavelengths of light:

• Blue: Short Wavelength Light (S-Cone)
• Green: Medium Wavelength Light (M-Cone)
• Red: Long Wavelength Light (L-cone)

Usually when people talk about colour blindness, they are referring to the most common forms of red-green colour blindness, which are genetic conditions caused by a recessive gene on the X-chromosome, but there are other types as well.

Red-green colour blindness can be broken down into two main types:

Protan-type (“pro-tan”), which is a disorder of the first “prot-” type of retinal cones also called the L-cones (red), and Deutan-type (“do-tan”) which is a disorder of the second type of retinal cone also called the M-cones (green).

Types of Colour Blindness

Monochromacy and Achromatopsia

• Monochromacy and Achromatopsia describes a range of conditions that include rod-Monochromacy, S-cone Monochromacy and Achromatopsia.
• Sometimes these are collectively referred to as types of achromatopsia, as the word “achromat” meaning “no color.” However, not all cases of achromatopsia have “no colour” vision.
• Similar to other forms of colour blindness, achromatopsia can be graded as incomplete (partial) achromatopsia or complete achromatopsia (total colour blindness).
• Achromatopsia is often associated with light sensitivity, photophobia, and glare sensitivity.
• In some cases, low vision disorders such as progressive cone dystrophy or retinitis pigmentosa can cause a gradual deterioration of colour vision that eventually turns into complete achromatopsia.
• Trichromats, Dichromats, Monochromats are terms used in the vision science community to refer to different possible configurations of the human visual system having three (tri-), two (di-) or one (mono) channel of colour information.
• However, these terms are simplified to a great extent, because the true capability of a colour vision system also depends on the degree of overlap between the channels, “perceptual noise” within the channels, and the cognitive processing capability for deciphering these signals in the visual cortex of the brain.
• Most cases of colour blindness are considered anomalous trichromacy which means they are effectively operating at somewhere between trichromat (normal colour vision with 3 channels) and dichromat (2 channels).

Three Most Common Types of Colour Blindness:

Deutan 

Red-Green Colour Blind

Colour Cone Sensitivity: Green

Deuteranomaly is the most common type of colour blindness, affecting about 6% of men. It is characterized by a reduced sensitivity to green light, making it difficult to differentiate between shades of red and green.

• Deutan Colour Blindness (“do-tan”) is an anomaly of the “M” cone.
• The “M” stands for Medium Wavelength Light, which is generally seen as green light.
• In Deutan-type CVD, the spectral sensitivity of the M-cone is shifted toward longer wavelengths so that it effectively receives too much red light and not enough green light.
• A person with deutan colour vision deficiency may experience confusions between colors such as green and yellow, or blue and purple.
• Another common symptom is that green traffic signals appear to be a very pale green or sometimes white.
• Common colour confusion also occurs between pink and gray or white, especially if the pink is similar to a light purple.

Protan 

Red-Green Colour Blind

Colour Cone Sensitivity: Red

Protan (“pro-tan”) is the second most common and is characterized by a reduced sensitivity to red light. People with protanomaly have difficulty distinguishing between shades of red and green.

• Protan Colour Blindness (“pro-tan”) is an anomaly of the “L” cones.
• The “L” stands for Long Wavelength Light, which is generally seen as red light, mainly responsible for seeing red colours.
• In Protan-type CVD, the spectral sensitivity of the L-cone is shifted toward shorter wavelengths, so that it does not receive enough red light, and receives too much green light compared to a normal L-cone.
• Protan-type CVD includes protanomaly, which is a partial shift of the L-cone, and protanopia, which is a complete shift of the L-cone.
• It is estimated that about 25% of cases of red-green colour blindness are of the protan type.
• A person with protan type colour blindness tends to see greens, yellows, oranges, reds, and browns as being more similar shades of colour than normal, especially in low light.
• A very common problem is that purple colours look more like blue.
• Another common issue is that pink colours appear to be gray, especially if the pink is a more reddish pink or salmon colour.
• Another symptom specific to Protan colour vision deficiency is that red colours look darker than normal. For example, if red text is printed on a black background, it can be very hard to read because the red appears to be very dark.

Tritan

Blue-Yellow Colour Blind

Colour Cone Sensitivity: Blue

• Tritanomaly is a rare form of colour blindness that affects both males and females equally. It is characterized by a reduced sensitivity to blue light, making it difficult to differentiate between shades of blue and green, as well as yellow and red.
• Tritan Colour Blindness (“try-tan”) includes tritanomaly and tritanopia. It is also sometimes called blue-yellow colour blindness.
• Tritan colour blindness most commonly acquired later in life due to aging of the eye or a medical condition such as glaucoma and is only very rarely inherited from birth.
• Tritan colour vision is generally characterized by a reduced sensitivity in the blue-sensitive “S” cone cells. “S” stands for Short Wavelength Light.
• The retinal S-cone cells make up only about 1% of the approximately 6 million retinal cone cells, so when they are damaged or not functioning properly, it can easily cause a degradation to colour vision.
• Typically a person with a tritan-type colour vision deficiency does not see blue colours well, and may have difficulty seeing the difference between blue and green.
• Cataracts, glaucoma, and age-related macular degeneration can cause symptoms of Tritan colour blindness.
• Another factor that causes reduced sensitivity to blue is the yellowing of the crystalline lens within the eye: these cells do not regenerate and over a lifetime of exposure to light, especially UV light, the lens tends to become yellow in appearance and block the transmission of blue light, interfering with colour vision.
• Eventually, this yellowing also leads to cataracts that must be treated surgically.

The Science Behind EnChroma Lens Technology

EnChroma develops optical lens technology that selectively filters out wavelengths of light at the point where this confusion or excessive overlap of colour sensitivity occurs. EnChroma lenses alter the signal to the M (Green) and L (Red) photoreceptor cones in such a way that there is a greater colour contrast along the so-called “confusion line” for that individual.

Our lens technology increases contrast between the red and green colour signals, alleviating symptoms of colour blindness for a richer experience of the world. With the application of science, optics, mathematics and more than 10 years of clinical research, EnChroma continues to advance the field of colour vision research and bring new products to market that solve unique colour deficiency issues. Learn more about the accidental discovery of this revolutionary lens technology.

EnChroma lens technology increases contrast between the red and green colour signals, alleviating symptoms of colour blindness for a richer experience of the world.

Proven to Stimulate Your Brain’s Colour Vision Processing

A groundbreaking new study found EnChroma colour blind glasses, which are engineered with technically advanced spectral notch filters, can enhance colour vision for those with the most common types of colour blindness. Test subjects experienced immediate improvement, which persisted long-term even after subjects stopped wearing the glasses. The researchers also found that wearing the glasses stimulated the colour vision processing center of the brain

Will EnChroma Colour Blind Glasses Work for Me?

Colour blindness is not a singular condition. It encompasses a range of conditions, from mild to severe, that can cause each person to see colour differently. EnChroma glasses are designed to improve colour vision of people with forms of anomalous trichromacy, which are estimated to comprise four out of five cases of colour blindness. 

The most common types are Protanomaly and Deuteranomaly, which are forms of partial red-green colour blindness. In the most extreme cases, the complete absence of one of the cone photopigments, called Protanopia or Deuteranopia, are considered dichromats who would see no results from our glasses due to the complete inability to see red and green colour differences.

Reduced colour discrimination of shades of blue and yellow is called Tritanomaly, or Tritanopia which is not a type of what is commonly referred to as red-green colour blindness, but is also a form of colour vision deficiency. EnChroma glasses are designed to address most forms of red-green colour blindness and are not intended to assist the vision of people with Tritan-type deficiency or Dichromacy where only two of their three colour-sensing cones are functioning. Fortunately, most cases of colour blindness respond well to EnChroma spectral lens technology, enabling the perception of bright, vibrant colour.

Take a free Colour Blindness Test

EnChroma has taken colour blind testing to the next level. Unlike old and outdated Ishihara tests developed back in 1917, our new colour blind test uses the science of cone isolation to test the sensitivity of each of your eye’s three colour-sensing cones and scores them to show you how close or far you are from having normal colour vision. And, unlike any other colour blind tests on the internet, our new colour blind test can be taken while wearing EnChroma colour blind glasses so you can compare your before and after results to see the improvement in your colour vision deficiency.

A colour blindness test is quick and simple you will be shown a series of coloured circular images with numbers within them very similar to the images below, you simply select the number that you see. 

To find out if the EnChroma colour blindness glasses could help you, you can take a brief colour blindness test, please follow the link below, this will take you to EnChroma's website:

EnChroma Colour Blindness Test

What’s the difference between Outdoor and Indoor lenses?

EnChroma Outdoor Lenses are designed to enhance colour vision outdoors in bright sunlight or partly cloudy conditions and also serve as sunglasses delivering 100% UV blocking and glare protection.

EnChroma Indoor Lenses are designed to be used in typical indoor lighting conditions to enhance colour vision while performing activities including but not limited to school work, cooking, watching sports or movies, browsing the web, playing video games, board games art projects and so much more.

For best results, all EnChroma colour blind glasses should be used around bright, full-spectrum lighting. Where there is light, there is colour!

Features:

Proprietary Spectral Lens Technology: Our award-winning lens technology is the result of more than a decade of pioneering research by EnChroma scientists, and is uniquely engineered to enhance colour vision for people with colour vision deficiency.

Scientifically Formulated And Designed in Berkley CA: EnChroma’s eyewear is made in our medical device manufacturing facility where EnChroma technicians perform 100% of lens machining, assembly, and quality verification using a combination of imported and US components.

Best In Class Lens Material: Cx Lenses are first generation EnChroma lenses and are made of Trivex, whereas the next generation (i.e Outdoor Deutan, Outdoor Protan and Indoor Universal) are made of Polycarbonate.

EnChroma's next generation of lenses design delivers up to 35% better colour performance, renders whites and neutrals more accurately, but both generations of lenses are scientifically proven to stimulate your brain’s colour vision processing.

The naming system for Cx refers to the overall lens categorization that is standard in the lens industry to indicate the amount of light that is transmitted or filtered through the lens. Cx1 lenses are Category 1 filters (44-80% transmission) for indoor, lower lighting conditions and Cx3 lenses are Category 3 filters (9-18% transmission), typical for sunglasses and bright sun.

100% UV Protection: EnChroma lenses block 100% of the UVA and UVB radiation components in sunlight. According to the World Health Organization, UVA rays are unfiltered by the atmosphere and can cause the most damage to vision health.

Ultra Touch Anti Scratch Coating: To ensure a long service life free of scratches, our lenses are clad with an optically clear, thermal-crosslinked coating to provide added lens durability.

Clarity Enhancing Anti-Reflective Coating: Lenses without anti-reflection coatings reflect up to 12% of light back into your eyes. EnChroma lenses feature dual-surface anti-reflective coatings to reduce reflections by more than 90%.

Super Hydrophobic Top Coat: This water-repellent surface treatment makes the lens slippery so that dust and dirt can be easily removed with a quick wipe of the included microfiber cloth.

Extras: Signature box, hard case, EnChroma® cleaning cloth, microfiber carrying bag, user guide, and colourful balloons included.

Do You Wear Prescription Glasses? Try the Receptor Fitover to conveniently wear EnChroma glasses over your existing prescription eyewear.

Do You Wear Contact Lenses? Our standard (non-prescription) eyewear can be combined with your existing contact lenses to deliver comprehensive colour and clarity correction.

100% Satisfaction Guarantee: EnChroma backs up every purchase with our 60-Day Money Back Guarantee and 2-year Warranty.

Please Note: EnChroma lenses are an assistive device intended to aid colour perception and improve colour discrimination, but do not give the wearer normal colour vision. Results vary depending on the type and extent of colour vision deficiency.  Unless specifically directed, wearing of filtering eyewear of any type is not permitted while taking colour blindness tests.