Tower Bridge will transport you to Victorian London, telling the story of the city’s defining landmark from the very beginning. Immerse yourself in the architecture and engineering, and watch city life unfold in panorama from its high-level Walkways and Glass Floors. Time your visit just right, and you’ll even get to experience the magic of a Bridge Lift beneath your feet.
There is extensive information on Tower Bridge's accessibility features on the Tower Bridge Accessibility webpage, including information for visitors with visual impairment, hearing impairment and autism, as well as mobility impairment.
From the iWheeltravel blog:
Up there, the view is nice, but you have to look through the steel structure openings. There are small windows that you can open to get a better view, but there are not at wheelchair height. The most exciting thing for me was the wide see-through glass floor! I am not very comfortable with heights, so rolling 65 meters above ground was a bit scary! But once I was on the glass floor, I enjoyed it.