Magnetic resonance elastography (MRE) is a novel experimental technique for estimating the dynamic shear modulus of biological tissue in vivo and non-invasively. Propagating acoustic frequency shear waves are launched into biologic tissue via external mechanical actuator and a conventional magnetic resonance imaging (MRI) scanner is used to acquire spatial-temporal measurements of the wave displacement field with micron precision. Local shear modulus estimates are obtained by inverting the equations governing shear wave motion. Changes in tissue pathology may be accompanied by a stark change in tissue elasticity. As a result, MRE has appeal to healthcare practitioners as a non-invasive diagnostic tool. Recently, MRE-based modulus estimates have been obtained in animal liver, brain, and heart [2-7]. Here, for the first time, MRE was used to probe the shear modulus of mouse eye vitreous humor in vivo and non-invasively.