Sometimes we are glad when someone comes. Sometimes we are not. When someone has gone, and we do not have to deal with them, again, we can say I’m so glad to see the back of her!

It means to be rid of (an unwanted person or thing) and can range from a difficult report just finished to an interview:
 
Why Germany would be especially happy to see the back of Trump  
 
[The Guardian | LINK]

 Why Lewisham’s plans for Millwall’s Den really take the biscuit
[the article bemoans the Labour council’s approved plans for compulsory purchase of the land around the ground which could threaten the football club’s basic operations]  
 
These same qualities of resilience may be needed again after the decision this week by Lewisham’s Labour council to approve plans for compulsory purchase of land around the Den as part of a mass “regeneration” project. Millwall currently rent the land under threat, the loss of which could threaten the club’s basic operations.

They offered to buy it at a higher price. Lewisham chose to go with the developer Renewal, which is ultimately controlled by offshore companies with mysterious owners and whose plan involves shoehorning in 2,400 homes, the huge majority for private sale, as part of Boris Johnson’s ramped-up “New Bermondsey” vision.  
 
References:
[HITC | 09.09.16 | LINK]
[The Guardian | 09.06.16 | LINK]

It’s frequently used to express relief over something which has been stressful, difficult or unpleasant has now finished and is now in the past.
 
Is the Iran nuclear deal dead and buried?  
 
In theory, the Iran nuclear deal is still in existence. But only just.
 
The country has announced that it will no longer be bound by any of its restrictions in terms of the numbers or type of centrifuges that can be operated or the level of enrichment of uranium that it can pursue.
 
[BBC | 06.01.20 | LINK]

Furthermore, poor eyesight could refer to someone who is inattentive, unobservant or has no interest in their immediate surrounding, when perhaps they should.

Blind as a Bat: A Case of Mind vs. Body:

Almost 40 years before the publication of “Mind and Cosmos,” the philosopher Thomas Nagel laid out the difficulties scientists face in trying to explain how the human brain gives rise to consciousness. His essay, as influential as any in the philosophy of mind, is called “What Is It Like to Be a Bat?”

By emitting “rapid, subtly modulated, high-frequency shrieks” and comparing them with the echoes, Dr. Nagel wrote, bats create a finely detailed, three-dimensional mental map of their world. But we humans are fundamentally incapable of imagining — and understanding — the animal’s inner life. Subjective experience, he concluded, is irreducible to physical terms. And so even the most precise theory of the brain can never fully account for the existence of mental phenomenon.

[The New York Times | 21.07.14 | LINK]