This attribute allows the system to control eye movements.
Substructure of the attribute:
(<top-state> ^motor-link-eyes <ml>)
(<ml> ^target-item << omi cdc >>
^target << attention page-left page-right >>
^target-x <num1>
^target-y <num2>
^delta-x <num3>
^delta-y <num4>)
Not all of these attributes are required. If the target item is not
specified, the current target remains unchanged. If the target is
attention or a page, all later attributes are ignored
and the eyes are directed to the focus of attention or the
corresponding page. Otherwise, the other values are checked, with the
target values having precedence over the deltas. The numerical values
are in terms of an object-centered coordinate system which depends on
the current visual target. Implementation of output function: SaccadeEyes in motor.c