Chickens eyes shut

[Tomokoth]

My chickens were struck with Infectious coryza and at least 2 have their eyes shut and can't see. Can this be reversed or I have to put them down?

 

[Wyorp Rock]

Can you post some photos?
Do you know for sure it's Infectious Coryza - do you have a diagnosis?
Do they have a bad odor/rotten smell to them?

Infectious Coryza is a contagious respiratory disease. Symptoms can be treated with Sulfa drugs, but there is no cure. Birds that have been sick/recovered and those exposed will be carriers for life. They can shed the disease throughout there lifetime and become symptomatic during times of stress (molting, changes within the flock, secondary illnesses/conditions, etc.)

A lot depends on your goals. If you are breeding, selling, trading, etc. then culling, disinfecting and waiting for a period of time would be your best option.
Culling to help prevent the spread of disease is also a good idea if you have a large number of birds.

IF you keep/treat them, then closing your flock would be the right thing to do and practice bio-security so you don't spread illness to other people's property.

No one can tell you what to do. After you do more research/reading, get some testing, etc. then you can make a wise/sound decision of how you need to proceed.

http://www.poultrydvm.com/condition/infectious-coryza
https://articles.extension.org/pages/68127/infectious-coryza-in-poultry

Common Poultry Diseases
http://edis.ifas.ufl.edu/ps044