Proving that those warning labels are no joke, a 10-year-old boy from Greece sustained permanent vision loss after he burned a hole in his left retina with a green laser pointer toy.
According to the case report, published today in the New England Journal of Medicine, the injury occurred on the macula, a small area in the middle of eye’s internal back surface that has the highest density of light-sensing cells and is responsible for central vision.
The child was first brought in to a University of Thessaly ophthalmology clinic by his parents due to complaints of reduced sight. A quick examination revealed a sizable scarred hole. Advanced imaging techniques then determined that the burn had penetrated all layers of the macula and caused extensive withering of the surrounding tissue. Two smaller areas of retina damage were observed immediately below the hole.
An initial vision test showed that his unaffected right eye was 20/20, but his left was measured at 20/100; meaning the detail he could see on objects standing 20 feet away is comparable to what someone with average healthy vision could make out from 100 feet away.
“The patient’s vision has remained unchanged during 18 months of follow-up,” the authors wrote.
Unfortunately, the specialized photoreceptors that convert light into electrical signals and the neighboring neurons that transmit that information into the brain do not regenerate after such an injury. And, despite some exciting advances in this field, there are currently no medical interventions that can restore vision after the cells have died.
In instances of recent macular trauma, where further tissue death may occur, physicians can perform several versions of a procedure known as a vitrectomy. Yet patients who undergo vitrectomy very often go on to develop cataracts – making vision even worse until that too is addressed with surgery.
Dr Sofia Androudi, the paper’s lead author, stated that the boy most likely sustained his injury months to a year prior and waited to tell anyone. She told CNN that he admitted to shining the laser toy directly into his eye several times after his father purchased it from a street merchant.
Similar to looking at the sun, the intense energy in a laser can rapidly kill retinal tissue. Dr Ajay Kuriyan, a clinical spokesperson for the American Academy of Ophthalmology, explained to IFLScience that there are two ways this can occur: Cells that absorb the high-frequency light beams may rapidly expand and then collapse, resulting in a shock wave that damages the tissue; or the heat generated by the laser causes cells to burn, much like a magnifying glass on a piece of paper.
Given the dangers of laser pointers, it is illegal in many areas to sell devices with more than 1 milliwatt of power, and in the US, lasers over 5 mW are restricted. Thanks to unscrupulous sellers and the Internet, however, they remain easy to come by.
If you own a laser toy and are unsure of its energy capacity, err on the side of caution (and sanity) and keep it away from eyeballs.