Distinguish between 眼睛 (Yǎnjīng) eyes and 眼镜(Yǎnjìng) glasses
In different city or province people have very different pronunciations, we call it "方言"(dialect),so I don't know the situation in other cities, I'm a beijinger,I can tell how beijingers distinguish these  two words.眼睛 the last word 睛 will be light reading, but 眼镜 the last word 镜 will be normal reading, otherwise,beijingers used to add a "er" pronunce in some specific words ,such as眼镜er,but 眼睛 has no 'er' pronunce.