Liz Buchanan BVSc MRCVS
Hello again - thankyou for the picture. The eye in the picture looks very enlarged / pushed forward, with nearly 50% of the globe exposed, compared with the small amount of eye usually exposed to the outside world (see other eye, perhaps, or a normal kitten's eye, for comparison). I am unable to say what has caused this, but your vet will be able to see more and therefore have an idea. Perhaps the eye has developed incorrectly or there is something behind it pushing it forward, or perhaps the pressure in the eyeball is very high (glaucoma) or something else. A secondary problem may be that the tear film is not correctly distributed over the top, leaving the globe vulnerable to drying, ulceration and damage and potentially extremely sore. Your vet - and / or second opinion vet - will also be able to tell you what amount of sight the kitten is likely to have going forward. There may also be other problems or infections present and they, having examined the kitten, are the best people to advise you about this.
It may be that the best option, if the prognosis for sight is low, is to remove the eye completely. Cats do very well with a single eye. Again, this may be affected by other underlying problems.
Bets of luck and please do let us know how you get on. In the short term, it may be very important to have sufficient and appropriate pain relief for the kitten.