Plastic lenses turn LED streetlights yellow and dim over time
Technology
Modern street lighting is locked in a race against entropy as high-intensity blue light slowly shatters the molecular chains of the plastic lenses meant to protect them.
While traditional glass is nearly immune to the sun and heat, the plastic lenses used in modern LED streetlights are slowly suffocating the light they emit. These polymers allow engineers to precisely shape beams to illuminate a highway without wasting light on the sky, but they come with a hidden expiration date. Under the constant bombardment of high-energy blue light and summer temperatures reaching 85 degrees Celsius, the clear plastic begins a process called chain scission, where the long molecular strands of the polymer literally break apart.