Looks like a retained spectacle.
It should be common practice to examine every shed in order the make sure both spectacles have come off.
As for oil or other substances permeating the cap - highly unlikely - I wouldn't worry about it.
In the meantime, if you can't afford a vet, leave her alone until the next shed cycle. If the eye swells or if the shape becomes irregular, you will have to take her in.
As for stuffing her in a a bag, or bathing her or mucking with what you think might be a retained spectacle - don't. Just leave her alone while making sure all her husbandry parameters are correct.
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