Introduced here are retinal cameras having optical stops whose size and/or position can be modified to increase the size of the space in which an eye can move while being imaged. In some embodiments, an optical stop is mechanically moved to recover retinal image quality as the subject shifts their eye. In some embodiments, an optical stop is digitally created using a pixelated liquid crystal display (LCD) layer having multiple pixels that are individually controllably. In some embodiments, multiple non-pixelated LCD layers are connected to one another to form a variable transmission stack, and each LCD layer within the variable transmission stack may be offset from the other LCD layers. In such embodiments, the optical stop can be moved by changing which LCD layer is active at a given point in time.