许多上了年纪的人,读书看报时要戴上老花镜,这样就能看清上面的字了,除此以外,老花镜还有其它的妙用呢。妙用之一:演示凸透镜对光线的会聚作用放学回家,借用爷爷或奶奶的老花镜,用手摸一摸,可知它是中间厚、边缘薄的凸透镜,白天将凸透镜对准太阳光,如图1,前后移动透镜到地面的距离,直到地 Many elderly people read reading newspapers to wear reading glasses, so that they can see the above words. In addition, there are other magical effects of reading glasses. One of the magical uses: Demonstrate that the convex lens converges on the light to go home and use Grandpa or Grandma’s reading glasses to touch it. It can be seen that it is a convex lens with a thick middle and thin edge, and the convex lens is aligned with the sun during the day. 1, move the lens back and forth to the ground until the ground