Whilst I don't think anyone is ever going to suggest a degree will do you any harm, what I would say is don't go into getting a degree because you think it will guarantee you a job in the rail industry. Plenty of folk have degrees these days, but plenty of folk alternatively have vocational qualifications and, indeed, good solid experience. Some TOCs seem to want degrees for pretty much every grade of staff, and others it's most common for staff *not* to have them. Indeed, degrees are horrendously expensive, will take up three to four years of your life, and you really need to have an interest for that subject in order to be able to get the most benefit from the course. That said, if you were unsuccessful at joining the railway initially a degree may allow you to work in that more specialised field when you need a job afterwards.
Some railway management roles may require you to meet a certain level of visual acuity, so it's worth bearing that in mind, though many won't. Any role in which you'd be carrying out Safety Critical work, or work which requires you to have PTS for going on the tracks, this is likely to be the case, though the visual requirement may not be as onerous as that for a driver.
Using the specific example of a Customer Service Manager as suggested upthread (eg Customer Experience Manager, Onboard Manager, Station Manager, whatever you want to call it at your TOC etc etc) these generally either come from a previous customer service management background (some TOCs prefer to take on externals with experience managing casual dining restaurants, for instance) or promoting them from the grades of staff they are managing (eg a Train Manager may go on to be promoted to an Onboard Manager). There's also some scope for lateral transfers from similar industry management roles and also outputs from Graduate Training Schemes etc, though places on these tend to be quite limited versus the demand. So for that, as an external, you'd either be looking to come in through a graduate scheme or with previous experience in a customer service management role.