Critical isomerohydrolase in the retinoid cycle involved in regeneration of 11-cis-retinal, the chromophore of rod and cone opsins. Catalyzes the cleavage and isomerization of all-trans-retinyl fatty acid esters to 11-cis-retinol which is further oxidized by 11-cis retinol dehydrogenase to 11-cis-retinal for use as visual chromophore (PubMed:16096063, PubMed:19805034, PubMed:20100834). Essential for the production of 11-cis retinal for both rod and cone photoreceptors. Also capable of catalyzing the isomerization of lutein to meso-zeaxanthin an eye-specific carotenoid (By similarity). The soluble form binds vitamin A (all-trans-retinol), making it available for LRAT processing to all-trans-retinyl ester. The membrane form, palmitoylated by LRAT, binds all-trans-retinyl esters, making them available for IMH (isomerohydrolase) processing to all-cis-retinol. The soluble form is regenerated by transferring its palmitoyl groups onto 11-cis-retinol, a reaction catalyzed by LRAT (PubMed:15186777). an all-trans-retinyl ester + H2O = 11-cis-retinol + a fatty acid + H(+) lutein = (3R,3'S)-zeaxanthin all-trans-retinyl hexadecanoate + H2O = 11-cis-retinol + H(+) + hexadecanoate Binds 1 Fe(2+) ion per subunit. Interacts with MYO7A; this mediates light-dependent intracellular transport of RPE65. Undergoes light-dependent intracellular transport to become more concentrated in the central region of the retina pigment epithelium cells (By similarity). Attached to the membrane by a lipid anchor when palmitoylated (membrane form), soluble when unpalmitoylated. Retinal pigment epithelium specific. Palmitoylation by LRAT regulates ligand binding specificity; the palmitoylated form (membrane form) specifically binds all-trans-retinyl-palmitate, while the soluble unpalmitoylated form binds all-trans-retinol (vitamin A). Belongs to the carotenoid oxygenase family.