The features of a paralytic squint include:

• usually acquired
• diplopia is present
• diplopia is maximal when attempting to look in the direction requiring the action of the weak muscle
• the image from the paralysed eye is always peripheral to the image from the normal eye
• the angle between the longitudinal axies of the eyes varies during testing of eye movements

A paralytic squint is caused by damage to extraocular muscles or their innervation.