discernible

Very easy to see or notice.

Can be noticed without difficulty.

Quickly and easily noticeable.

Extremely difficult to see or notice.

Can be noticed instantly, without any delay.

Almost impossible to see or notice; more formal than 'barely'.

Can be noticed, but only with effort; barely noticeable.

Used to state that something can be seen, heard, or noticed.

Used to describe the process of something starting to be noticeable.