We studied a synthetic hydrogel, PHEA [poly(2-hydroxyethyl acrylate)], experimentally. The material is transparent, autoclavable , highly viscous, nonabsorbable, easily injectable, cohesive, and does not fragment on passage through small-gauge needles. Results in animal studies revealed that injection of PHEA into the vitreous cavity promoted inflammatory changes such as vitreous haziness , membrane formation, and chorioretinal atrophy. Histopathologic studies showed extensive retinal disorganization, chorioretinal scarring, and vitritis . We reviewed the literature and concluded that an ideal vitreous substitute for long-term use in complex cases of retinal detachment is not available at this time.