PRK removes the thin surface layer of your cornea (epithelium).Your eye surgeon then uses a laser to flatten your cornea or make its curve steeper.是什么意思_PRK removes the thin surface layer of your cornea (epithelium).Your eye surgeon then uses a laser to flatten your cornea or make its curve steeper.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句