le'otci lujvo

t1 is a monocle/pair of (eye)glasses/spectacles for observational activity t2.

Cf. lenjo, tutci, barkalyle'o, vistci.

In notes:

barkalyle'o
l1=b1 is a monocle/pair of (eye)glasses/spectacles allowing the clear sight of l2 (light) by k2 (wearer).
cmactatci
t1 is a microscope used by t2=ca1 for looking at small things t2=ca2=cm1 which are small in property/dimension(s) cm2 (ka) as compared with standard/norm cm3.
darctatci
t1 is a telescope for examining c2=d1 which is far from d2.
darvistci
t1 is a telescope for seeing v2=d1 which is far from d2.
vistci
t1 is an optical tool used by v1 to see v2.
lacni
x1 is an eyewear used/worn by x2 serving purpose x3.