1. Mahlaseli a ultraviolet a ka senya cornea le retina.Ha leihlo le fumana khanya e ngata haholo, ka tlhaho le kopana le iris.Likhalase tsa letsatsi tsa boleng bo holimo li ka sefa ho fihla ho 97% ea khanya e kenang mahlong ho qoba kotsi.
2. Likhalase tse mebala-bala tse khanyang ha e le hantle ke mefuta e mengata ea feshene ea li-visor tsa letsatsi.Le hoja li thibela letsatsi ka tlaase ho li-visor tsa letsatsi, morero oa tsona oa motheo ke ho phetha karolo ea ho khabisa.Ba ratoa ke bacha ba itšetlehileng ka mebala e ruileng le mekhoa ea feshene.Lilemong tsa morao tjena, basali ba feshene ba se ba rata likhalase tse joalo tse loketseng ho lumellana le liaparo tse sa tšoaneng.
3. Likhalase tse khethehileng tsa letsatsi ke mofuta o ntlafalitsoeng oa li-visor tse tloaelehileng tsa letsatsi.Lipontšo tsa tsona li phahame ho feta tsa likhalase tse tloaelehileng tsa letsatsi, 'me li na le mosebetsi o moholo oa ho thibela khanya e matla.Ka kakaretso, ba na le litlhoko tse fapaneng bakeng sa liketsahalo tse khethehileng.Hangata li sebelisoa lipapaling tsa ka ntle moo letsatsi le leng matla 'me le hloka pono e ntle, joalo ka lebōpo la leoatle, skiing, ho hloa lithaba le golf.
