1996 Cud Or Eye Lid

It wouldn't be a Cud because Cuds are die breaks that form on the rims of coins. While it does have the shape of a tilted eyelid, it might just be a plating bubble (zinc rot) where bubbles of gas form under the plating and raise it. They can and do take on unusual shapes. Notice the "mole" (raised dot) just NW of the corner of Lincoln's mouth. That might be one in the same.

Can you zoom in a lot closer and also post a pic of the reverse?

The "mole" is a mole,it was part of the design. By the eye it looks like a die chip to me. Odd shape for a gas bubble,IMHO.
John1

I'm aware of the mole in the design. It just looked enlarged here. Maybe it's the lighting.

As to the raised area west of the eye, I thought of die chip first but it's so large that it would be considered a an interior die break and even be listable in that section on cuds-on-coins. It would be nice if it was a die break but I think we would have seen this before. I couldn't find it.

Hence, my guess at a large plating bubble to rule out that possibility, pending more detailed pics.

With anything but a Zlincoln, this is clearly a die break. However, when you strike coins in a metal which reacts with just about anything, the sky is the limit for weirdness underneath the skin.

As profiler said in the first reply to your question, this cannot be a Cud. Cuds happen at the rim. I do see what looks like a crack running south from the feature in your new images; if it is in fact a die crack then we should probably assume the feature is a die break.