So, according to what you say, you are quite dependant on laptop for reading needs. But I should remind you that laptop, and some other electronic devices would give out a lot of radiation and harmful lights, which do harm to your eyes if your eyes are constantly exposed to those screens. Of course it is true, so what you should do is to take breaks at intervals and get some food good for your eyes. Just pay more attention to your eye health and it would be ok.
Yes, the laptop screen is bad for eyes if you spend too much time reading on it. Actually, any kind of light screen is bad for eyes if we watch at it for a long time. Especially, when we watch it in a dark enviroment. To avoid eyes problems, we should keep up a good habit of watching screen, taking a break when you can.
Your mom is right, it's really bad for your eyes if you spend too much time reading on laptop screens. Because the light resource from the screen will be directly come into your eyes which saves the process of coming into your retinal, your eyes may get tired easily. What's worse, the eyes axis will elongate because of the too much use of eyes. Then you will be easily myopia. Besides, the dryness symptom may come to your eyes. However, I do not mean that you can not reading on laptop, but if you want to do it, you had better change the brightness of your computer less bright and do not see the computer screen for long time, to avoid have dry eyes and redness. In a word, keep a good balance between the rest and laptop, you can enjoy your reading time.