A. Good Light Reaction in Both Eyes

1. Simple anisocoria - no dilation lag of smaller pupil
2. Horner Syndrome [1]
   1. Lesion of sympathetic neurons controlling ocular structures
   2. Ptosis (eyelid droop), miosis (pupil constriction), anhidrosis (lack of tearing)
   3. Preganglionic / Central
   4. Postganglionic
   5. Distinguish by 1% hydroxyamphetamine test

B. Poor light Reaction in One Eye

1. CN III Palsy
2. "Atropinic Mydriasis"
3. Iris Damage
4. Adio's Tonic Pupil
5. Acute closed angle glaucoma

References

1. Miller NR and Newman NJ. 2004. Lancet. 364(9450):2045