Career
She is best known for her work on gravitational lensing, including the Chang-Refsdal lens. Chang was born in Seoul. She worked as a research associate on astrometric binaries with Professors van de Kamp and Heintz at Sproul Observatory from 1969 till 1971.
From 1975 until 1980 she worked on a Doctor of Natural Sciences at Hamburg University, graduating with her work on the Chang-Refsdal lens.
The main result was published in Nature in 1979 immediately after the discovery of the first gravitational lens. She returned to of Korea in 1985 and became a professor at Cheongju University.
