Hi,
Tamoxifen was known to cause side effects related to vision earlier, when the doses used were much higher than the currently used dose schedules.
You should still report any abnormal features that you notice when on the medication , to your doctor.
It would also help to get a opinion from an eye specialist.
What other symptoms are you having?
Have you been on any medications for this?
Let us know about how you are doing and if you have any other doubts.
Regards.
You can google Tamoxifen for more info but it has been associated with eye problems in some women. I would definitely let your Dr. know.