Screen door effect can be described as a black grid over the
original image. This occurs because of empty spaces in
between the pixels. The display has a characteristic known
as the Pixel Fill Factor that is responsible for this effect. On
any LCD display every pixel is made of three sub pixels,
namely red green and blue. Human perception of different
colors on the display is a result of the varying intensities of
these sub pixels. The distance between these sub pixels is
called as the pixel pitch which ultimately decides the pixel
fill factor. Higher the pixel pitch higher is the pixel fill
factor. The oculus rift has a fair pixel fill factor however
since it is worn close to the eyes it gives rise to the screen
door effect.
Ghosting is the appearance of faded trails behind any
moving object. In oculus rift, the slow pixel switching time
causes ghosting i.e. the pixels take a fair amount of time to
change intensities as compared to the motion of the head.
Faster the movements greater the ghosting, since the pixel
switching lags behind. Thus ghosting persists until the head
stops moving. This causes blurring of the scene. Ghosting
can be avoided with a higher switching rate for the pixels.