Kia ora Michael,
Welcome to Cancer ChatNZ. I’m not sure that the symptoms you have are related to tamoxifen. While some medications used to treat breast cancer can cause watery eyes this is mostly seen with chemotherapy rather than tamoxifen. Tamoxifen side effects can include a slightly increased risk of cataracts and dry eye.
It would be good to discuss your symptoms with your GP.
Thank you for your message.
Kind regards,
Julie, Cancer Information Nurse