Blinking is how we spread tears across the surface of our eyes. The eyelids function like little squeegees or windshield wipers. The tears that we make minute-to-minute to lubricate our eyes are spread from up and out to down and in on our eyes. In a perfect set-up the front of the eye remains moist with a smooth tear surface for the entire time between blinks.
A normal adult blinks about 12 times every minute. Regular tears stay on the eye for 10-12 seconds before they break up, so if you blink 12 times a minute you always have a smooth, complete tear layer covering your eyes.
Certain activities cause us to blink less. Reading, looking at a computer, or driving in the rain all require more concentration. During these activities the blink rate decreases, sometimes by as much as half! If your tears do not stay smooth between blinks you can then have all of the symptoms that we associate with Dry Eye. Burning, tearing, a foreign body sensation, and blurring all occur when we blink too infrequently. Reading doesn't cause your eye to become dry, but because we naturally blink less when we read (or use a computer) reading can cause the symptoms of dryness to be worse.
There are many solutions to this, and the one that is best for you depends on things that can only be seen during an eye exam. If you have these types of symptoms when reading you may have a type of Dry Eye that is made worse when you blink less.