They're floaters.

The wings are vitreous (transparent) with light brown veins.

Whether or not this slope can be moved by other objects, like floaters.

And I started to see floaters and stars, which I casually dismissed as too much high altitude sun exposure.

It involves the removal of the vitreous gel and is usually combined with filling the eye with either a gas bubble (SF6 or C3F8 gas) or silicone oil.