"Subsequent visits" refers to future or later visits. It means that someone has already visited once before and this phrase describes the visits that come after that initial one. Full definition
For example, if on a previous visit you went to our marketing pages, we might find this out from your cookie and highlight marketing information on subsequent visits. (educationbusinessuk.net)
Some clinics charge more per appointment because they make you pay an examination fee with each visit; others just charge for the vaccines during subsequent visits. (smartdogowners.com)
In subsequent visits as needed «fine - tuning» of residual issues could be achieved by new visual exercises. (MomsTeam.com)