Yes. If the pain is from the iris, and you constrict one iris, then the consensual response based on the nerves is for the other iris to constrict also and thus you can get pain in both eyes.
Yes. This effect is most commonly seen with iritis and bright lights. Patients experience photophobia or sensitivity to bright lights and the pain appears to occur in both eyes. This is due to the fact that the pupils constrict together regardless of the source of the light and cause the sensation of pain in both eyes.
Rare. Most migraines with an effect on the visual system usually cause the same phenomenon visually in each eye (cover one then the other to detect this). A very rare spasm of vessels in one eye only causes unilateral migraine but this is rare. Test your migraine if you have another and you can find the source which is probably the occipital lobe in the brain. Read more...