Differences between paralytic and non-paralytic squint

Features Paralytic squint Non-paralytic squint
1. Onset Usually sudden Usually slow
2. Diplopia Usually present Usually absent
3. Ocular movements Limited in the direction of action of paralysed muscle. Full
4. False projection It is positive i.e., patient cannot correctly locate the False projection is
object in space when asked to see in the direction negative
of paralysed muscle in early stages.
5. Head posture A particular head posture depending upon the muscle Normal
paralysed may be present.
6. Nausea and vertigo Present Absent
7. Secondary deviation More than the primary deviation Equal to primary deviation.
8. In old cases patho- Present Absent
logical sequelae in the
muscles