There is none
optical axis passing through centeres of cornea,lens to retina.visual axis is line passing through fixation point to fovea.
difference between an observaton and explanation
Difference between what? See related question
expansion difference
whta is the difference between a manned and unmanned spaceflight
There is no difference between lense and lens. All is the same.
the name
The lens size is the only difference the XL have a bigger lens.
The diffrence between thick and thin lens depends on your precription for your eyes.
one is single lens and the other is multi lens
It's about a $300-400 USD price difference.
converging lens show virtual and real images while diverging shows virtual images.
the ocular lens sits higher up, closer to your eye. the objective lens are in the objective tube below the ocular lens
The pinhole camera has no lens. The human eye has a variable-focus lens.
Convex lens converges the light and a concave lens diverges the light..
Double lens goggles don't fog up as easily and are more durable than single lens.
simple microscope only have 1 lens and compound microscope uses 2 lens \