Why Does the Eye Sink or Shoot Up in Duane Syndrome?

It can be startling to see your child’s eye suddenly sink backward or shoot upward when they try to look in a certain direction. These movements—called globe retraction (the eye pulling back) and upshoots or downshoots (the eye darting vertically)—are classic signs of Duane retraction syndrome (DRS), a condition present from birth. It is important to know that these movements do not mean the eye is “weak,” nor do they typically cause pain. Rather, they are caused by a unique mechanical “tug-of-war” and a “leash effect” resulting from how the eye muscles are wired ^[1]. Furthermore, these physical symptoms usually remain stable and do not progressively worsen as your child grows.

The “Tug-of-War”: Why the Eye Sinks Backward

To understand why the eye sinks into the socket, it helps to look at how eye muscles normally work. Typically, when you look toward your nose, the inner eye muscle (medial rectus) pulls, and the outer eye muscle (lateral rectus) relaxes.

In Duane syndrome, there is a miswiring of the cranial nerves in the brainstem ^[2]. The nerve that usually commands the outer muscle to pull the eye outward is missing or underdeveloped ^[1][3]. Instead, the nerve controlling the inner muscle sends branches to the outer muscle too.

When your child tries to look toward their nose, both the inner and outer muscles receive the signal to pull at the exact same time ^[4]. This simultaneous pulling is called co-contraction ^[5]. Because the muscles on both sides of the eye are pulling against each other in a literal tug-of-war, the eyeball has nowhere to go but backward into the eye socket ^[6]. This backward movement is known as globe retraction. When the eye pulls back, the eyelids naturally lose their support and drape over the eye, which is why the eye opening suddenly looks narrower (narrowing of the palpebral fissure) ^[7][8].

The “Leash Effect”: Why the Eye Shoots Up or Down

When the eye is pulled into this tight tug-of-war, the muscles are under intense tension. As your child’s eye turns inward toward the nose, the extremely tight outer muscle (lateral rectus) gets stretched across the rounded surface of the eyeball.

If you imagine stretching a thick, tight rubber band over a slippery ball, you can picture what happens next. If the tight muscle slips slightly above or below the center of the eye, it acts like a tight leash snapping. The tension forces the eye to suddenly shoot upward (upshoot) or downward (downshoot) ^[9].

While this sudden darting motion is primarily mechanical (the “leash effect” of the tight slipping muscle), researchers have noted that miswiring of the nerves connected to the vertical eye muscles can also play a role in certain cases ^[9]. Structural differences, like extra fibrous bands around the eye muscles, might also contribute to this tight restriction ^[10][11].

What This Means for Your Child

These movements can look strange or alarming, but they are a known and predictable part of the anatomy of Duane syndrome. While tools like glasses or prisms can sometimes help with an abnormal head posture or overall alignment, they cannot fix the mechanical “leash effect” or the eye sinking.

If the upshoots, downshoots, or globe retraction are causing significant issues—such as an awkward head tilt, cosmetic concerns, or vision problems—there are highly individualized surgical options available ^[12][13]. Surgeons can use specific techniques (such as “Y-splitting” the muscle or moving its attachment point) to reduce the mechanical tension, stop the slipping, and prevent the eye from pulling backward ^[12][14].