Schiaramento/annotazione:For objective determination of eye refraction by the method of shadow ïðîáû-ñêèàñêîïèè.
Descrizione del marchio dettagliata:Composition:
1ëèíåéêà with positive lens and movable frame,
1ëèíåéêà with negative. lens and movable frame.
the measurement limits of refractions with gradation 0. 5 äïòð: from +9 to - 9 äïòð.
measurement limits of refraction with gradation 1 äïòð:
from +10 to +19 äïòð, from - 10 to - 19 äïòð.
length: 350 MM.
width: 40 MM .
mass of each ruler: 0. 2 kg. |
