My mother is going to the ophthalmologist because of keratitis.

The amygdala is a part of the brain that controls our emotions.

He read the small print using a magnifying glass.

He was drawing a figure using a set square.

I'm fed up with his crappy posts.

He was trolling on the bulletin board.

He distinguished himself in that project.

His olfactory organ is very sensitive.

He cannot smell due to a problem with his olfactory organ.

I use a set square to draw shapes.