She ate flock raiser and is now on layer pellets. She gets scratch and occasionally we throw ruffage veggies, metalwork treats and oat balls their way. They have a pecking block.
Lovely photo of you both!
To me her eyes look normal.
From what you say, it's possible she may have always had a bit of difficulty seeing(?) it's just now a bit more noticeable since she's lagging behind a bit.
Sometimes a bird can hatch blind or there's a developmental issue.
You may find that she will need supportive care - making sure she's getting to food/water, coming in earlier.
Folks do keep blind birds - they do make accommodations, keeping food/water in the same place and providing them with a secure place to sleep. She may not be able to see well enough to roost high, but she may do ok if you provide her a low shelf she can settle on at night.
She may see well enough and hear the flock to keep up with them during the day, but as time goes by, she may struggle more and need to be confined to a run so she's not separated. A bird that can't see well is going to rely heavily on the others, she may have a buddy/friend that sticks with her, you'll have to watch and see.