How are the disk membranes in rods different from those in cones?

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details of the mammalian eye — Photoreception The mammalian eye has a cornea and a lens and functions as a dioptric system, in which light rays are refracted to focus on the retina.

In vertebrate photoreception, both rods and cones feature outer segments composed of numerous pancakelike disks that house photopigments. The primary structural difference between them lies in their connectivity to the surrounding environment:

Rods: The disks are closed off from the surrounding fluid.
Cones: The disks are partially open to the surrounding fluid.

This structural arrangement, along with the high density of photopigments like rhodopsin, allows these cells to effectively absorb photons and generate the necessary output signals for vision.1