PHOTOCHROMIC SUNGLASSES CYCLING

photochromic

Photochromism is the reversible transformation of a chemical species between two forms by the absorption of electromagnetic radiation, where the two forms have different absorption spectra. Trivially, this can be described as a reversible change of colour upon exposure to light.
Able to change lens color or darkness/density depending upon the degree of exposure to light.
(of a substance) Undergoing a reversible change in color or shade when exposed to light of a particular frequency or intensity
(Photochromics) Glazing with the optical properties that change in response to the amount of incident light.

sunglasses

Glasses tinted to protect the eyes from sunlight or glare
(sunglass) a convex lens that focuses the rays of the sun; used to start a fire
spectacles that are darkened or polarized to protect the eyes from the glare of the sun; “he was wearing a pair of mirrored shades”
Sunglasses or sun glasses are a form of protective eyewear designed primarily to prevent bright Sun light and high-energy visible light from damaging or discomforting the eyes.

cycling

(cyclist) a person who rides a bicycle
Cycling, also called bicycling or biking, is the use of bicycles for transport, recreation, or for sport. Persons engaged in cycling are cyclists. or bicyclists.
The sport or activity of riding a bicycle. Bicycle racing has three main forms: road racing (typically over long distances), track racing (on an oval track), and cyclocross (over rough, open country)
the sport of traveling on a bicycle or motorcycle

photochromic lens

photochromic lens