Ho tloha qalong ea nako, thepa ea bongaka ea leseli e 'nile ea tsejoa le ho sebelisoa bakeng sa pholiso. Baegepeta ba boholo-holo ba hahile li-solarium tse nang le khalase e mebala ho sebelisa mebala e itseng ea spectrum e bonahalang ho folisa maloetse. E ne e le Baegepeta ba ileng ba qala ho hlokomela hore haeba u daea khalase e tla sefa maqhubu a mang 'ohle a spectrum e bonahalang ea leseli 'me e u fe mofuta o hloekileng oa leseli le lefubelu, e lengMahlaseli a bolelele ba maqhubu a nanometer a 600-700.Tšebeliso ea pele ea Bagerike le Baroma e ne e totobatsa liphello tsa mocheso tsa leseli.
Ka 1903, Neils Ryberg Finsen o ile a fuoa Khau ea Nobel ea bongaka ka ho sebelisa khanya ea ultraviolet ka katleho ho phekola batho ba nang le lefuba. Kajeno Finsen o tsejoa e le ntate oaphekolo ea sejoale-joale ea phototherapy.
Ke batla ho le bontša bukana eo ke e fumaneng. Ke ea mathoasong a lilemo tsa bo-1900 'me ka pele e baleha tjena 'Natefeloa ke letsatsi ka tlung le khanya ea lapeng.' Ke sehlahisoa se entsoeng Brithani se bitsoang Vi-Tan ultraviolet home unit 'me ha e le hantle ke lebokose la ho hlapela la khanya ea ultraviolet incandescent. E na le tleloubu ea incandescent, lebone la mouoane oa mercury, le ntšang khanya ka har'a ultraviolet spectrum, e leng se tla fana ka vithamine D.