Each of the following sentences:
今ではほとんど見ることのできないポケットベル、通称ポケベルは、当時の女子高校生の必須アイテムだった。
Pokebell, the short version for Pocket Bell in Japanese, can’t hardly be seen now but it was the indispensable item for female high school students of that time.
鼻より先を見ることのできないものもいる。
Someone cannot see beyond the end of his nose.
顕微鏡でしか見ることのできない生物。
An organism that can be seen only through a microscope.
has the "見ることのできない" but the translation is different, like in example 2, the sentence is talking about someone that can't see something, but in sentence 1, the sentence is talking about something that can't be seen.
How do Japanese interpret these sentences?