Antoniadi scale
parallax
optical astronomy
telescopy
eyehole
scopeful
skytime
metrology
reflector
reflectometry
astronomics
observatorial
umbraculate
telescopic
femtoscale
areographer
semiempirical
subvisually
ultrasonographics
opticianry
monocular
visual modality
ocularity
radio observation
solar telescope
observatory
telescopically
vision
Y level
sight
visual sense
astrointerferometer
visuoconstructive
International System
stargazing
SI system
SI
SI unit
Systeme International d'Unites
International System of Units
visuoconstructional
observing
eye test
Systeme International
perspective glass
Schmidt telescope
-scopy
observational
field glasses
experimental