Is there a link between insulin resistance and vision loss?

Association: Perhaps indirectly. Insulin resistance is associated with diabetes mellitus and of course, diabetes may lead to a variety of complications which result in vision loss.

Not by itself: The strongest link is between elevated or fluctuating blood sugars and blurred vision. Unstable blood sugars cause fluid shifts in the eye's lens which in turn causes vision instability. Prolonged high blood sugar can cause damage to the small blood vessels in the film layer (retina), which can lead to permanent vision loss.