Yes, light is considered a mass noun.
A mass noun (also called a non-countable noun) refers to something that cannot be counted individually and doesn’t typically have a plural form. Mass nouns are used with singular verbs and are generally not used with “a” or numbers unless they’re referring to specific quantities (like “a piece of light”).
Light fits this category because it refers to an abstract or uncountable concept, not something that can be counted directly (e.g., “I saw some light,” not “I saw lights” unless referring to specific light sources like lamps or bulbs).
So, in general, light is treated as a mass noun when referring to the phenomenon itself, as in “There is light in the room” or “The light is bright.”