Merriam-Webster Collegiate Dictionary - refract

 transitive verb  Etymology: Latin ~us, past participle of refringere to break open, break up, from re- + frangere to break — more at break  Date: 1612  1.  a. to subject (as a ray of light) to ~ion  b. to alter or distort as if by ~ion to ~ that familiar world through the mind and heart of a romantic…woman — Anton Myrer  2. to determine the ~ing power of