An astigmatism test determines whether the curvature of your cornea or lens is normal; an abnormal curvature will sharply focus some portions of an image onto your retina, while blurring others.
Astigmatism is very common among children and can have a negative impact on academic success since it causes confusion between letters and numbers.
Place yourself at approximately 3feet from the screen.
Cover one eye with your hand and take the test. Cover the other eye and begin the test again.
If some of the lines appear grayer and some blacker; consult your eye care specialist.