With a digital SLR camera the dioptre of the viewfinder can be optimally adjusted for the photographer's own vision. Approximately 90 per cent of all people who wear spectacles then get along just fine without them. However, purchasing a so-called correction lens is really only worth it if your vision is strongly impaired – by a dioptre greater than 6. The correction lens is screwed onto the viewfinder and makes it possible for you to see clearly through it without spectacles.
Many digital SLR cameras are also equipped with a LiveView function. The rear display shows directly what the digital sensor sees and what is saved as a photo when the shutter button is pressed. For a final check that the picture is in focus, you can zoom in on the subject with the magnification function. That gives you the security that you have photographed the subject perfectly. Many compact and mirrorless system cameras have only such a display for viewing the subject. In bright sunlight, however, these displays are at a significant disadvantage in comparison to a viewfinder. And only the photographer with a viewfinder will have a clear and glare-free view through the lens.
People with presbyopia have a real advantage when photographing without spectacles. It's true they can no longer see close-up very well and have to hold the newspaper as far away as possible in order to be able to read it. However, since the refractive power of the viewfinder is calibrated so that objects at a distance of one meter are in focus, the sight problem is thus rectified. You can see clearly and sharply and there is nothing to prevent you from taking a great picture.