D
- D-segment
- decentration
- depth perception
- design reference point
- differential light sensitivity, S
- differential luminance, DL
- digitally rounding focimeter
- dimensions of lens blanks or lenses
- dioptre
- dioptric power
- Direct ophthalmoscope
- dispersion
- display magnification
- display size
- distance cap
- Distance dependent ophthalmometer
- distance design reference point
- distance optical centre
- distance portion
- distance portion curve
- distance reference point
- distance visual point DVP
- diverging lens
- dividing line
differential light sensitivity, S
Ratio of the background luminance LB to the threshold differential luminance DLT DL = LS - LB


