First of all you need an account on the ophthalmologia.be website. If you do not yet have an account, you need to contact the office and request an account to be made for you. You will need to supply a valid email address and you need to inform them your status (are you ophthalmologist, Resident in Training, Nurse, ...). You can contact the office on email@example.com.
Once you have the account you can login with your email address along with a password of you choose.