"Sunken eyes" is a term describing the eyes that is skinny and unhealthy. As we all know that e if someone's eyes have massive bags under them, his eyes are likely sunken eyes. Apart from this symbol, sunken eyes are always associated with the shape of the people, namely, if the people is very skinny and there is no fat on their face, which will make their eyes look "sunken". However, there is a point for you to notice, if you see someone's eyes are so-called sunken, but there is much or some fat on their face, then you cannot call the eyes sunken eyes instead of the deep eyes. Because the deep eyes and sunken eyes are very similar and some people always mix the up, if you are not sure which one the eyes are, you had better call them sunken eyes, which will be impolite. Hope this can help you know the sunken eyes better.
