1. Donders FC (1864) Accommodation and refraction of the eye, with a preliminary essay on physiological dioptrics. (W. D. Moore, Trans.). London: New Sydenham Society. 188–193.
2. Visual acuity changes throughout adulthood in normal, healthy eyes: Seeing beyond 6/6;DB Elliott;Optom Vis Sci,1995
3. Visual acuity as a function of age;DG Pitts;J Am Optom Assoc,1982
4. Aging and the haptic perception of 3D surface shape;JF Norman;Atten Percept Psychophys,2011
5. Aging and spatial acuity of touch;JC Stevens;J Gerontol,1992