Brian has a medical condition called cone dystrophy, which is a disorder of the cone cells in the eye. What symptoms would you expect Brian to have?

Cone dystrophy is manifested by the loss of acute visual acuity (which cannot be corrected with glasses), severe sensitivity to light (photophobia) and blind spots (scotomas) in the peripheral vision, which progress and produce poor vision in dimly lit or dark environments ("night blindness") and total loss of the peripheral visual field, which can be progressive.

Explanation:

Rod and cone dystrophies (CRDs) are inherited retinal dystrophies. They are included in the group of retinitis pigmentosa, and, more generally, in that of retinopathy pigmentosa. Cones are responsible for color and detail vision. Cone dystrophy is a disease of hereditary degeneration of the cone receptors, whose hallmark includes the "trilogy" of progressive loss of central visual acuity, disturbance in color vision and sensitivity to light (photophobia) which can be progressive.