Fully Colorblind People See Their First Burst Of Vibrancy For The First Time

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A small group of volunteers who have experienced full colorblindness since birth were able to catch a glimpse of color for the first time after undergoing retinal gene therapy.

The condition, called achromatopsia, affects approximately one in 30,000 people, leaving them to see only changes in light—instead of hues—all throughout their life. Due to a single gene mutation that affects the functioning of cone cells in the retina, the development or function of their cones is disrupted, leading to the absence or severe impairment of color vision.

At present, there is no cure for full colorblindness, but specialized glasses and contact lenses may help.

Israeli researchers wondered if they could treat this abnormality by inserting functional copies of the affected gene into cone cells, so that’s what they did.

To their delight, the participants—three adults and one child—were able to see red after the procedure, though to a very limited degree. They could distinguish red stripes against dark backgrounds, which would have been otherwise impossible. The team has detailed its research in a new paper published in Current Biology.

While the progress is undoubtedly encouraging, the scientists observed that the reliance on rod cells, responsible for peripheral and low-light vision, may have posed a hindrance to the participants’ ability to perceive colors fully.

The active rod cells might have interfered with the treated cone cells’ capacity to generate color signals, thereby limiting the extent of color vision experienced by the volunteers.

Due to the lack of functional cones, affected individuals rely on their rod cells for vision, which are responsible for peripheral and low-light vision. This results in reduced visual acuity, especially in bright lighting conditions.

When the “achromats” were asked to describe their first sighting of the color red, they said there were “no appropriate words,” recalls Ayelet Mckyton, a neuroscientist at the Hebrew University of Jerusalem and one of the researchers behind the study.

When pressed further, the subjects said the stimulus “glows differently, shines, or appears on a different plane.”

Impressively, a year after the surgery, the patients still pretty much react to red in the same way,

[via ScienceAlert and Current Biology, cover image generated using AI]

This article was crafted with assistance from an AI engine, and has been reviewed, edited, and fact-checked.