Lines are Blurry, please help

This setting may have an influence:

Try to activate "Use Graphic Processor" under Preferences > Performance... (don't forget to restart Photoshop)

Magnification is the solution: at 90% or 110% you need to use an odd multiplication factor wich will make your lines « pixelated ». At 100% a pixel on the image can be represented by one pixel on screen. That gives you the best view. Generally 25%, 50%, 100%, 200% etc are easy and fast to calculate and give a good quality. Anything in between would need more complex calculation and aproximation. For performance reasons the interpolation is done with a simple method. What you see at 100% is the correct display.