Patient presents with unequal pupils. What is your diagnosis?

Some additional info regarding the patients history and physical:

1. Acute onset.  Driver's license does not demonstrate that this is a chronic physiologic anisocoria. 
2. Anisocoria is greater in light than dark.  Abnormal pupil is the larger one. 
3. There is no ptosis or extraocular muscle palsies.  Third nerve palsy is unlikely. 
4. No recent eye trauma.  Iris appears intact on slit-lamp examination.  Iris sphincter muscle damage is unlikely. 
5. Denies getting any mydriatic substance in the eye ie atropine, scopolamine patch, ipratropium bromide, pseudoephedrine.  Unlikely pharmacologically induced. 

A physical exam maneuver was performed and a presumed diagnosis made.  What is the test and diagnosis? Scroll down for answer.

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Abnormal pupil had no reaction to light but a slow constriction to prolonged near stimulation (looking at thumb), a light-near dissociation.  Diagnosis: Adie's tonic pupil.   To learn more about this entity, click here.

Source

Wills Eye Manual: Office and Emergency Room Diagnosis and Treatment of Eye Disease

Practical Neurology DVD Review

Image source: https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgJqnAA4APhM7xTgXm6h5i6QJ0H-RABpqH3LQn8UYQEu197ouNyvg33oHQhFUonpvKuuT9lJRHJoi73sKEQsOl-gf5OLGX_XNzK-DzX0CfdV781GrmjryQFFhp3LF96DCYNkSS8g_sLH1Ml/s400/Anisocoria.jpg