As mentioned above, there are various types of nystagmus eyes depending upon the eye movements and the age at which it develops. In vertical nystagmus, there are involuntary and rapid eye movements in the down beating or up beating direction, which is why it is referred to as ‘vertical’.
On the other hand, in horizontal nystagmus, the eye movements are from side to side. There are several causes of horizontal nystagmus like stroke, optic nerve disorders, lack of pigmentation in the skin, and more.