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 Pupillary Light Reflex  

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If you shine light from a pen torch in one eye, you get the direct and consensual pupillary reflexes, and both pupils constrict by equal amounts.

What happens if you shine light using two pen torches, one in each eye, but with different intensities? I think that both eyes will constrict by equal amounts, to the size appropriate to the highest light intensity, but I'm not sure. Or perhaps light input from both eyes summates in the pretectal and Edinger-Westphal nuclei, and both eyes respond appropriately to this?

If anyone has a reference I can look up I'll be very very grateful.

Thanks everyone,



Thats more for an opthamology service/Step 1 is basic. Good luck!


both pupila will be the same size...anisocoria ( dif in size ) is likely due to an EFFERENT defect.....
afferents from the visual pathway cross over and project bilaterally no dif in size between the two pupils in an afferent pathway


i agree with studying as far as i understand light reflex isnt it all or none?

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