With a powerfull lens or magnifying glass, obviously 
But the best technique, is not to look through your lens and at your disc, as though you were viewing the disc from --> straight above, instead angle your disc at about 45% away from your eye so you look over it at an angle (like a plane coming into land, the disc is the runway, and your eye is the pilots eye).
You also need to have a light on, or the sun shining, be carefull reading them in bright sunlight, as the reflection of the sun of the disc could definately damage your eyes.
It seems a lot clearer that way, I doubt many of us can loose the magnifying glass, but its definately better to angle it away from you. 
This is a bit trivial I know, but I struggle to read rings, fullstop. And I am just trying to help those in this situation, like me.
The SPICE must flow.
