In a certain class, 10 people changed their myopia at the beginning of the term. After treatment, 8 people changed their myopia at the end of the term examination. How many percent lower than that at the beginning of the term?
某班开学初换近视眼的有10人，经过治疗，期末检查时还有8人换近视眼，比开学初降低了百分之几？
<gadget id="calculator">10 - 8</gadget>
<output>2</output>

<gadget id="calculator">2 / 10</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>