"My eyes."

Translation: Mo shùilean.

[Coiseam]

i thought we only use plural when there are 3≤ articles? weren't the double and single rules the same?

[Arwasaynemane]

That's only when the numeral dà two is actually present, so even though we know that someone saying "my eyes" has two of them, the plural is used as normal. You could make of this mo dhà shùil my two eyes and then you wouldn't use a plural.

Some higher numerals do not take a plural noun either, e.g. fichead sùil '20 eyes'. It's really not so much the quantity expressed that determines the use of plural noun forms, but the specific requirements of the numeral that is used along with the noun.