My left eye vision is 4.8, and my right eye vision is 5.1. Which eye has better vision? How much is the difference?
我的左眼视力是4.8，右眼视力是5.1，哪只的眼睛视力好些？相差多少？
<gadget id="calculator">5.1 - 4.8</gadget>
<output>0.3</output>

<result>0.3</result>