<prompt> All are true about concomitant squint except:Angle of primary deviation is equal to angle of secondary deviationDiplopia usually presentThere is no limitation of movementPosition of head is normal  <response>: Ans: b Diplopia usually present Ref: Khurana, 4th ed, p. 321Squint is a tough topic as far as postgraduate entrance exam is concerned. But there is no way out.Atleast try to learn the difference between concomitant and inconcomitant squint byheart. That will help a lot.Squint:Misalignment of the visual axes of the two eyes is squintType: Pseudostrabismus or apparent squint Heterophoria or latent squintHeterotropia or manifest squint--- a Concomitant--- b InconcomitantApparent squint: Visual axes parallel but eyes seem to have squintPseudo esotropia app. Convergent - e.g., prominent epicanthal foldPseudo exotropia app divergent - e.g., hypertelorismHeterophoria latent squintTendency of eyes to deviate is kept latent by fusion types Exophoria-tendency to diverge Esophoria - tendency to converge Hyperphoria - tendency to deviate upwards Hypophoria - tendency to deviate downwards Cyclophoria - tendency to rotate around anteroposterior axisTreatment of heterophoria decompensated1. Correct refractive errors2. Orthoptic treatment3. Prescription of prism glasses4. Surgical treatmentHeterotropia manifest squint - Cover test confirms heterotropiaTypes:1. Concomitant: Amount of deviation in squinting eye constant in all directions of eye2. Incomitant: Amount of deviation varies in different directionsConcomitantIncomitant Convergent esotropia Divergent exotropia Vertical hypertropia Paralytic A and V pattern heterotropias Special ocular motility defects e.g., Duane retraction syndrome,Browns oblique tendon sheath syndromeTests in paralytic squint Diplopia charting Hess screen test Field of binocular vision Forced duction testDifferentiating features between concomitant and incomitant squint Incomitant squintConcomitant squintMagnitudeVaries with eye positionSame in all positionDiplopiaPresentNormalOcular movementsRestrictedFullFalse projectionPresentAbsentAbnormal head posturePresentAbsentSecondary deviation primary deviationEqual to primary deviationTreatment of manifest squint1. Treatment of the cause2. Conservative measures-vit B, steroids, wait and watch policy3. Treatment of diplopia4. Surgical treatmentLaws governing ocular movements:1. Herrings law of equal innervation2. Sherringtons law of reciprocal innervation 