It often feels difficult to read some lines on your web browser. This is because some sites have small fonts or because that your font settings are different. The simplest way to solve this is by changing font size by a shortcut which is almost accepted by all browsers.
I dont know wether it works on Mozilla Firefox or not so please try it. This is can be done by going into the browsers settings but it will be complicated. The easiest way to do this is by the shortcut Control + plus. You can either press the button on the number pad or the one to the left of the backspace key. To reverse it, I mean to make it smaller you have to press Control + minus.
An image of google zoomed in google chrome is given. And remember that changing font size doesnt affect the size of images.
I have seen people zooming into web pages to see small text. ,,,, And this is also a solution for those who use spectacles to see text correctly. Try it.....