Pope Francis prescribed a simple solution to the gloom and despair of sick and disabled persons and the families taking care of them: the "therapy of the smile."

In his homily during Sunday's Mass in St. Peter's Square, the Pope lamented the current thinking in today's world that the sick and the disabled cannot be happy, and should be kept out of sight from society.

"In an age when care for one's body has become an obsession and a big business, anything imperfect has to be hidden away, since it threatens the happiness and serenity of the privileged few and endangers the dominant model," the Pope said, according to the Catholic News Service (CNA).

Pope Francis said it is wrong to think that sick and disabled persons "cannot be happy since they cannot live the lifestyle held up by the culture of pleasure and entertainment."

"In some cases, we are even told that it is better to eliminate them as soon as possible, because they become an unacceptable economic burden in time of crisis," he said, apparently referring to the growing appeal of physician-assisted suicide for the terminally ill.

He said there are people who want the sick and disabled to be kept apart from society in "enclosures" or on "'islands' of pietism or social welfare, so that they do not hold back the pace of a false well-being."

Pope Francis said these people "fail to understand the real meaning of life, which also has to do with accepting suffering and limitations."

He underscored that happiness can only be achieved "if we are capable of loving."

"How many disabled and suffering persons open their hearts to life again as soon as they realise they are loved! How much love can well up in a heart simply with a smile! The therapy of the smile. Then our frailness itself can become a source of consolation and support in our solitude."

The Pope reminded the faithful that everyone of them will one day face – often painfully – "frailty and illness, both our own and those of others."

He said when that time comes, some people may become cynical, "as if the only solution were simply to put up with these experiences, trusting only in our own strength."

Others may put their trust in science with the belief that medicine has a cure, despite the fact that this is not always the case, he said.

Faced with this situation, "the temptation to become self-absorbed grows stronger, and we risk losing life's greatest opportunity: to love in spite of everything," the Pope said.