Ucas application help!!!

I want to do an eye related course in uni (optometry/orthoptics), but there are only 2 universities in Scotland that do any of the related courses that I want to do (Optometry and Orthoptics at Glasgow Caledonian and Optometry at UHI), would it be okay to only have 3 choices in my UCAS application or would i need to fill up all 5 choices?

No you don't need to use all 5 choices.
(Any reason why you can't apply for courses over the border?)

Its too expensive for me to do so and I'm not really interested in going anywhere else other than Scotland. People have told me that i should use up all 5 of my choices.

You don't have to use up all 5 slots. That's entirely up to you.

I want to do an eye related course in uni (optometry/orthoptics), but there are only 2 universities in Scotland that do any of the related courses that I want to do (Optometry and Orthoptics at Glasgow Caledonian and Optometry at UHI), would it be okay to only have 3 choices in my UCAS application or would i need to fill up all 5 choices?

if thats what you want to study and where you want to study it then there wouldn’t be any point applying elsewhere or to any other courses because if you didnt get onto one of these 2 you probably wouldn’t take up a place on an unrelated course or outside of Scotland. You dont have to fill up all your 5 choices at all, are the requirements for the 2 courses you mentioned in line with your predicted grades?

For orthoptics yes, for Optometry I need another A and I'm not sure what my predicted grades are for My subjects (I'm doing advanced higher chemistry, biology and crashing higher business)

It might be worth asking your school about predicteds and explaining that you’re only going to have two choices (so one firm and one insurance) to see if they can be lenient with that. Either way, being only slightly below asking should be fine if you have a strong ps etc as it’ll give you something to work towards.