If Bumble is keeping her eye closed or is squinting, then she may have injured her cornea in some way; even the smallest scratch can be quite painful which is usually denoted by squinting or keeping the eye closed ....either partially or completely.
If this is the case, then she'll likely require need topical antibiotics as well as topical pain drugs which your vet will have to dispense.
It's also possible that the eye is just really irritated because of some sort of trauma. If she has only slightly irritated the eye, you may be able to treat her at home.
Without applying a special stain, we can't know for sure what might be the problem. However, I do have a few suggestion which may help:
1. You can apply a warm washcloth or warm tea bag to the eye/area for about 5-10 minutes which may provide relief. This can be repeated 2-3 times a day if you'd like.
2. You can gently rinse the eye with over the counter saline solution which should be available at most human pharmacies (at least this is true here in the States). You don't want to use the contact lens solution, though.
Unfortunately, there are no over the counter antibiotic ophthalmic drugs that you will be able to purchase; these types of drugs are all prescription and would have to be dispensed by your vet. However, the following otc human products are also ones which can be used. I'm not sure what you might have available to you in the UK but, hopefully, at least one on the list can be found.
The Systane products which are listed can be applied, but the ones with vasoconstrictors, such as naphazoline should be avoided. These products are labeled as "taking the red out" or for "red eye".
Tears Naturale Nighttime
Systane Ultralubricant sterile eye drops
Advanced Eye Relief Nighttime
Akwa Tears ointment
I recommend treating 3 times a day for usually 5-7 days.
If there's no improvement and/or the eyes look worse, then a vet visit may be wise.
I hope this helps, Deb