Also, you're not using the native mode of your monitor.
Think about it this way: The image is made of lit pixels. If a single pixel has to be drawn, a single "lamp" is lit in the monitor. On or off, no dimming. If you change the resolution to less than native, that single lamp won't light up since you can't lit it partially only. Similarly, when there's two pixels only one of them is lit. With three only two and so on. Since a plane is a cross shaped thing there's thin lines to four dimensions so you may be missing a lot more than a single pixel especially when the said cross is a slanted one pixel wide bunch of dots. So while others may see an "X" you may see the very center of it as a ".".
The lower resolution turns into your advantage when the dot grows wider than a couple of pixels, at that point you may see your target better. Your video card is capable to keep a constant 60 fps at the native resolution so the lowered resolution doesn't smoothen the motion. If it does there's something else wrong in your system.