Primary angle-closure glaucoma (PACG) is the second most prevalent form of glaucoma, with a high rate of blindness and often a clinical emergency, with few to no prior indications. In PACG, the anterior chamber angle is blocked by the iris root, causing sudden elevation of IOP and subsequent neural damage. The standard treatment includes topical administration of a cholinergic drug, e.g., Pilocarpine, to contract the pupillary sphincter and subsequent iridectomy to eliminate the iridal obstruction and increase the aqueous outflow facility. In some patients, PACG develops acutely with no prior indications of angle closure, while in others, a chronic progression can be detected, causing gradual IOP elevation. Although having Asian descent, crowded anterior chamber, and stiff iris have been indicated as risk factors (i.e., angle-closure suspects, ACS), the exact mechanisms of PACG are not known. Based on the preponderance of the evidence, it is clear that there is a connection between iridal deformations and PACG; still, the role of iris biomechanics, especially iris deformations during mydriasis/miosis, remains unknown. In our studies, we aim to evaluate iris biomechanical properties, such as iridial muscle forces, and the associated deformations to assess them as risk factors for PACG using ex vivo and in vivo measurements.