visual-line-fringe-indicators

visual-line-fringe-indicators is a variable defined in `simple.el'.
Its value is

(nil nil)

Documentation:
How fringe indicators are shown for wrapped lines in `visual-line-mode'.
The value should be a list of the form (LEFT RIGHT), where LEFT
and RIGHT are symbols representing the bitmaps to display, to
indicate wrapped lines, in the left and right fringes respectively.
See also `fringe-indicator-alist'.
The default is not to display fringe indicators for wrapped lines.
This variable does not affect fringe indicators displayed for
other purposes.

You can customize this variable.