There are two main types of absence seizures: typical and atypical absence seizures. Both types are short in duration and may be mistaken for daydreaming. Typical seizures are more common than atypical. They occur when a person suddenly ceases their activity and stares off into space. They may have a blank expression, and their eyes may turn upwards. They do not last more than ten seconds. Atypical seizures last up to twenty seconds and are characterized by a change in movement and muscle tone, such as smacking the lips, chewing, and repeated blinking.