Another important aspect of lighting a space for those with diminishing eyesight is visual cuing. Visual cuing provides an additional reference point for judging distance or depth when entering a space or approaching objects. The lighting at the base of these cabinets or toe-kick lighting contrasts well with the dark floor and midtone cabinetry creating a readily visible contrast. But people will just think it's cool.
However a grid of pot lights is not all you need for a balanced light scheme. Notice that this space also includes a pendant sconces and art lamps (more on those later) as well as a full wall of windows. Including at least three layers of light from different categories and in different locations eliminates strong shadows and adds a sense of sparkle that allows all the other furnishings to look their best.
When hanging a light over a table or a kitchen island 28 to 34 inches is the recommended distance from the bottom of the light to the surface of the table or island. However the size of the light makes a difference. In general a smaller light can be moved lower and a larger light can be moved higher.