The retina is the part pf the eye that is similar to the film of a camera. It is a thin layer of cells that is located at the back of the eyeball. This part contains photoreceptor cells which respond to light where the neural signals received undergoes complex processing by other neurons in the retina.
Technician A is correct, there could be water or other contaminant in the brake fluid reservoir. The swollen cap needs to be replaced, some sell only the rubber part of the cap which could help save you money.
