Color blind glasses work by filtering out specific wavelengths of light that cause confusion between colors, and the core technology behind them is surprisingly straightforward in concept. But recreating it at home is extremely difficult. The lenses require precision optical coatings deposited in laboratory conditions, not something you can assemble with off-the-shelf parts. Here’s what actually goes into making these glasses, what a DIY attempt would look like, and where the realistic boundaries are.
How Color Blind Glasses Actually Work
Most color blindness happens because your red-sensing and green-sensing cone cells in the retina overlap too much in the wavelengths they respond to. When those cones fire at nearly the same time for the same light, your brain can’t tell the difference between red and green. Color blind glasses solve this by cutting out a narrow band of light right in the overlap zone, typically around 590 nanometers (the yellow-orange range). By removing that shared signal, the glasses force your red cones and green cones to respond to more distinct slices of the spectrum, giving your brain cleaner data to work with.
This type of filter is called a “notch filter,” and it’s the same basic technology used in laser safety goggles, astronomical imaging, and LIDAR systems. The difference is that color blind glasses need to block a very precise, narrow band while letting everything else through with minimal distortion. That precision is what makes them expensive and hard to replicate.
The Manufacturing Process Behind the Lenses
Commercial color blind lenses are made through a process called thin-film deposition. Alternating layers of materials with different refractive indices are deposited onto a glass or polycarbonate substrate, often dozens or even hundreds of layers, each only nanometers thick. When light hits these layers, some wavelengths reflect back and cancel themselves out through interference (the same physics that creates rainbow patterns on soap bubbles). The result is a filter that blocks a targeted slice of the spectrum with remarkable accuracy.
This coating happens inside a vacuum chamber where temperature, deposition rate, and chamber geometry all need precise control. Companies in the optical filter industry use plasma deposition processes to build these coatings, and even small variations in layer thickness shift the filter’s performance. You can’t paint this onto a lens. You can’t achieve it with colored film. The physics only works when each layer is controlled at the nanometer scale.
EnChroma, the most well-known brand, uses a proprietary version of this multi-layer notch filter technology. Their lenses are designed to block the overlap wavelengths cleanly while keeping the overall color cast minimal. Budget brands like Pilestone use simpler tinted lenses that lean more heavily on a red or green tint to shift color perception. Users consistently report that Pilestone lenses add a noticeable color haze to everything, while EnChroma’s filtering is subtler and fades into the background over time. The trade-off is price: EnChroma glasses typically cost $200 to $350, while Pilestone options run $40 to $80.
Can You Build a DIY Pair?
In theory, yes. In practice, you’d be spending more money for a worse result than buying a commercial pair. Here’s what the attempt would involve.
You’d need to source an optical notch filter that blocks the right wavelength band. Scientific suppliers like Edmund Optics sell individual bandpass and notch filters. A single 25mm-diameter bandpass filter centered at 590 nanometers costs around $199, and that’s just one small round disc of glass, not a pair of lenses shaped for eyewear. You’d need two, plus a way to mount them in frames, and you’d still have filters designed for laboratory instruments rather than human vision. They wouldn’t be curved to fit standard glasses frames, they wouldn’t have anti-reflective coatings for comfortable wearing, and the optical quality across your field of view would be poor compared to purpose-built eyewear.
Some hobbyists have experimented with theatrical lighting gels (colored plastic sheets) cut to fit cheap sunglasses frames. A magenta or rose-tinted gel can crudely approximate what color blind glasses do by absorbing some of the yellow-green overlap wavelengths. The result is similar to what budget brands offer: a heavy color tint over everything, marginal improvement in distinguishing reds from greens, and an unpleasant viewing experience for extended wear. It costs almost nothing, so it’s worth trying if you’re curious, but it’s a novelty rather than a functional tool.
The Red Tint Problem
Cheap filters and DIY approaches almost always produce a strong red or orange tint. This is the fundamental challenge. Blocking the overlap wavelengths without also distorting the rest of the spectrum requires the kind of precision multi-layer coating that only vacuum deposition can achieve. Simple colored filters block too broadly, which is why Pilestone users frequently describe everything looking like it’s been dipped in orange, and why several report they can’t wear the lenses for more than a few minutes before the visual distortion becomes uncomfortable. EnChroma’s advantage isn’t magic; it’s tighter manufacturing tolerances that keep the notch narrow and the rest of the spectrum clean.
How Well Do These Glasses Actually Perform?
The honest answer is: less dramatically than the viral videos suggest. A study examining EnChroma’s filters found that color discrimination scores on standard clinical tests were not clearly improved for most participants. The one exception was people with protan-type color blindness (reduced red sensitivity), who showed some improvement on pattern-based color tests. For deutan-type color blindness (reduced green sensitivity, which is the most common form), the filters didn’t reliably improve performance and in some cases actually introduced new errors by shifting the type of mistakes participants made.
Red-tinted contact lenses, which work on a similar filtering principle, showed more promising results in a pilot study. Participants with milder color vision deficiency saw up to 80% improvement in error scores on the Ishihara plate test (the booklet of dotted number patterns used to diagnose color blindness). Those with more severe deficiency still saw around 50% improvement with the best-performing lens type. But these are test scores, not real-world color perception, and the study was small.
What users consistently report is that the glasses don’t let you “see new colors.” They make existing color differences more obvious. Reds look more distinctly red. Greens pop more against brown backgrounds. Flowers in a garden look more varied. For many people, that’s genuinely meaningful even if it doesn’t register as a clinical improvement on standardized tests.
Who These Glasses Can’t Help
Color blind glasses only work for people who have all three types of cone cells but with overlapping sensitivity, a condition called anomalous trichromacy. If you’re completely missing one type of cone (dichromacy), there’s no overlap to filter out and the glasses won’t create color information that your eyes can’t detect. People with complete color blindness (monochromacy) get no benefit at all.
The distinction matters for anyone considering a purchase or a DIY project. If you have mild to moderate red-green color blindness, where you can see some difference between red and green but they look muddy or similar, filtering glasses have the best chance of helping. If you’ve been told you have severe protanopia or deuteranopia (complete absence of red or green cone function), the glasses are unlikely to produce meaningful results.
Software Alternatives That Cost Nothing
If your goal is practical color accessibility rather than a physical gadget, software solutions are free and available right now. Both Windows and macOS have built-in color filters that shift the display to make colors more distinguishable for color blind users. iPhones and Android phones offer the same. These work through algorithms called daltonization, which mathematically transform the colors on screen so that information normally carried in the red-green channel gets redistributed into channels you can perceive, like blue-yellow contrast or brightness differences.
Software can’t help you see the real world differently, but for tasks like reading color-coded charts, distinguishing status lights in apps, or interpreting maps, they’re often more effective than glasses. And unlike a physical filter, they introduce zero color distortion to the parts of the spectrum you already see normally.