Lazy or sick?

Hi guys
This may be silly but I needed yalls opinion as I'm not experienced and this is my first mischief.
I have 3 boys and my cream colored boy Casper in my opinion is a just a lazy potato rat but my girlfriend seemed concerned. Concerned if this is normal behavior or if there could be something wrong with him.

All three have very different personalities but the other two are for most part quite energetic.

Casper from the get go has always been reserved, hes not the type of rat you can reach in and pick up. He has to come to you and it definitely took a lot more patience and effort to bond with him but now he does come to us and allows us to pet him and hold him compared to before that if u disturbed him through the bars hed move away to where he cant be bothered.

He spends most of his time napping he loves napping and rarely comes down to greet us unless theres snacks involved in which I got to be honest majority of the time we just deliver the snack directly into his hands in the hammock bc it takes him too long to wake up and waddle down to the first floor lmao. So he just eats his snacks with his eyes closed. Which again I just think hes lazy AF. Lol

Always catching him with his eyes half open or squinting. If not completely closed.

I read ruby eyed rats typically are more vision impaired or more susceptible to being blind.

Other than him just being lazy and his constant squinting theres nothing really wrong with him from what I can observe.
He breathes just fine, he eats and poops just fine. He doesnt groom as well as my other boys but again I chalk it up to being lazy.

I got all my 3 boys from the same craigslist post they are all the same age more or less I've had them since they were 6 weeks and I believe they are approximately 12 weeks now if not 13 weeks.

I'll include two pictures of him, when he was little and had his eyes nicely open and to how he is now with squinty half opened eyes.

Hi newbie. Your boy Casper, at 12 weeks, is too young to be that lazy. Squinty eyes are never normal. They’re a sign of pain or eye problems.He does have a lot of porphyrine around that eye, indicating some issue with it, and it’s obvious he’s not grooming well, as you said. The fact that he’s reluctant to move much suggests he feels very bad. He looks quite alert and healthy (and super cute,) in the young baby pic, so something has happened to make him feel bad. Hold him gently and examine him all over, looking for bumps, wounds, or any place that pressure elicits a pain response. It would be best if you can take him to a good vet with rat experience. I’m sorry, but he’s not just lazy; he needs help.

Is that the same boy who had the tip of his tail get constricted and amputated?