Turn the settings down, don't get thermal obsessed and stare through it too much, it's not good for your eyes. Thermal bino's don't give you the eye burn, but are a nightmare weight wise to stalk with, esp. if you are also carrying glass binoculars!! from a car, you can't beat thermal bino's for spotting.
I wear contact lenses, and find that I have to use thermal spotters with extreme moderation, otherwise I will also get flashing lights for hours and some pain like you. Same with HIK and Pulsar as an FYI, use all three brands as we test our competitors regularly, and they all do the same.
regularly go to opticians and get checked out, and they say some eyes are just more sensitive to intense light, and this can be esp. magnified by contact lenses.
I wear contact lenses, and find that I have to use thermal spotters with extreme moderation, otherwise I will also get flashing lights for hours and some pain like you. Same with HIK and Pulsar as an FYI, use all three brands as we test our competitors regularly, and they all do the same.
regularly go to opticians and get checked out, and they say some eyes are just more sensitive to intense light, and this can be esp. magnified by contact lenses.

