Dad's eyesight worsening. What could it be?

[IrisJoy]

I have just taken dd to the optician. We went last week and the optician couldn't come to any conclusion. He thought this was because she isn't great at wearing her glasses and her eye muscles were spasming.
She went beck today for them to put drops in to dilate her pupils and try again.
The (different) optician today cone to exactly the same results. She said dd's vision has deteriorated; but isn't to do with her glasses or prescription. Something else is going on.
She said she doesn't think it's anything sinister but has referred her to hospital for them to have a look.
The appointment won't be for months. Does anyone have any ideas what it could be to stop me googling worrying too much in the meantime?

Title should be dd. Stupid autocorrect!

Has she been tired, thirsty, going to the loo a lot or lost any weight? Sometimes type 1 Diabetes can cause eye issues that aren’t always obvious to an optician especially in young people- it’s how my DH was diagnosed.

Thank you for the reply. She hasn't shown any signs of diabetes so I don't think it's that.
I am sure it is something that's very minor. I just can't help worrying.

How old is she? My eyesight went from perfect to atrocious between 12 and 14.

I think be reassured by them saying they don't think it is anything sinister.

She will be 12 in February.
What was the reason yours got bad? Did it recover?
She has been slightly long sighted for a couple of years. Check up 6 months ago was same prescription.
She hasn't noticed anything but she is reading the line or two larger at the opticians (if that makes sense!) even with her glasses.

Has she had a growth spurt? My Dads prescription always gets worse if she has grown a lot since her last check.

She has had a bit of a spurt but they have said specifically it's not to do with her prescription but something else.

Mine went from fine to +6 in my teens. Basically my eye muscles had always compensated massively (so I could read all the letters) but couldn't do it anymore if I was tired, I also got a lot of headaches.

Even into my 20s if I took my contacts out in the waiting room my eyes would adjust so I could see fine by the time I had the test and had to sit in the chair with the prescription in trying to relax my eyes.

Could it be something like that?

I think they thought it was something like that, which is why they gave her the drops today. But now it seems not...
Thank you for the suggestion