Whilst I understand your frustration aly I think that perhaps you need to put yourself in his shoes - he's faced with a condition which has the potential to change his life beyond anything he can imagine - and without support and information his imagination will run riot with all the 'what ifs'.
If you are finding it hard to empathise and his constantly rehashing it all it getting you down, may I suggest checking out the Moorfields Eye Hospital website where you will find the details of a nurse helpline, available to anyone with concerns over eye conditions. It may reassure him and give him an opportunity to ask some questions which are clearly playing on his mind, if he were to give them a call. Having once used the line myself when I suffered an eye condition out of the blue, I can thoroughly recommend their service. They are both factual, practical and very helpful indeed. I hope that this may help both your DH and you to deal with his worries and put an end to the sulking which is very trying for you.
Here is the 'cut and paste' info from my internet search for their up to date number...see below:
You can also get information and advice on eye conditions and treatments from our telephone helpline, Moorfields Direct, on 020 7566 2345. Staffed by experienced ophthalmic-trained nurses, the helpline is open from 9am to 9pm, Monday to Friday and from 8.30am to 5pm on Saturdays.
Sending best wishes to you both 