Is your dog presenting with any other symptoms other than the haze over her eyes?
Are the eyes draining or red?
What tests did they perform on your dog when you went to the specialist?
Was the specialist an opthamologist?
Could you tell me her age again?
I assume they did all the pressure tests, stains, and tear testing since you went to the opthamologist. Right now and until we see how she responds to treatment this will be the only determining factor as to whether this is a virus or retinal degeneration. If she responds to the prednisone then her vision will return to normal or progression will be halted and may have been related to optic neuritis or other autoimmune disease. I wish I could tell you the likelihood of it being one or another but I cannot. The odds of it being related to SARDS is good given her age, sex, and sudden onset alone. The prednisone is in the system within hours after taking it and should reach dose appropriate levels within 2-3 days but treatment may continue for weeks depending on how or if she is responding. In dogs with SARDS complete blindness occurs anywhere from 1 day to 4 weeks. The vet may choose to treat based on this range. Blindness related to SARDS is not reversible or treatable. So her diagnosis will be based on her response to the medications. I am sorry to give you such disturbing news but do know that dogs who lose their eyesight adjust amazingly well. The only request they will have is don't move things around because they don't know where it is.
Please let me know if further assistance is needed.