These make the pupil of the eye larger and will be used on every visit to a retinal specialist, generally in both eyes. They prevent the pupil from becoming smaller when bright lights are used to examine the retina. It is impossible to examine the whole retina without these.
The drops blur vision, especially near vision, and cause a lot of glare even without bright lighting. It is important not to drive for at least 4-6 hours after the drops have been used and worth taking sunglasses to any retinal appointment.