Should he prostrate to Allah in gratitude for the blessing of hearing and sight?
Question

Is it permissible to prostrate and thank Allah, may He be glorified and exalted, for blessings such as the blessing of hearing? I hope that you can explain with evidence.
Praise be to Allah.The prostration of gratitude is only prescribed for new blessings, such as having a child, or the return of an absent loved one, or victory over an enemy, not for an ongoing blessing such as the blessings of hearing and sight, because that is not narrated in sharee’ah. If it were prescribed, it would mean that a person would spend his whole life prostrating out of gratitude. 
Al-Nawawi (may Allah have mercy on him) said in al-Majmoo’ (3/564): al-Shaafa’i and his companions said: The prostration of gratitude is a Sunnah when a new, obvious blessing comes and when an obvious adversity is warded off, whether the blessing or adversity affects the individual or all the Muslims. Our companions said: Similarly, if he sees a person who is afflicted with a calamity, physical or otherwise, or with sin, it is mustahabb to prostrate out of gratitude to Allah. But it is not prescribed to prostrate for ongoing blessings because they do not cease. End quote.   
Ibn Qudamah (may Allah have mercy on him) said in al-Mughni (1/363): It is mustahabb to do the prostration of gratitude when a new blessing comes or adversity is warded off. This is the view of al-Shaafa’i, Ishaaq, Abu Thawr and Ibn al-Mundhir. 
Ibn al-Mundhir narrated with his isnaad from Abu Bakrah that if news reached the Prophet (peace and blessings of Allah be upon him) that pleased him, he would fall down in prostration. Narrated by Abu Dawood. The wording is: If news that pleased him reached him, or he was given glad tidings, he would fall down in prostration, giving thanks to Allah. And al-Tirmidhi said: This is a hasan ghareeb hadeeth. Abu Bakr al-Siddeeq prostrated when al-Yamaamah was conquered, and ‘Ali prostrated when he found Dhu’l-Thadiyyah among the slain Khawaarij, and it was also narrated that a number of Sahaabah did this (offered the prostration of gratitude). End quote. 
Ibn al-Qayyim (may Allah have mercy on him) said in I’laam al-Muwaqqi’een (2/296): Blessings are of two types: ongoing and new. The thanks for ongoing blessings is given by doing acts of worship and obedience, and the prostration of gratitude is prescribed for new blessings, out of gratitude to Allah and to express humility and submission before Him, in return for the joy and delight felt because of the blessing. That is the best way to counter this feeling of excessive rejoicing, because Allah does not like those who rejoice excessively, so the remedy for this disease is submission and humility before the Lord of the Worlds. End quote. 
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said in al-Sharh al-Mumti’ ‘ala Zad al-Mustaqni’ (4/105): The words “when a new blessing comes” refer to new blessings as opposed to ongoing blessings. If we were to tell a man that it is mustahabb to prostrate for ongoing blessings, he would always be prostrating, because Allah says (interpretation of the meaning):
“and if you count the Blessings of Allah, never will you be able to count them”[Ibraaheem 14:34].
Ongoing blessings are ones an individual generally experiences constantly and are not newly or unexpectedly received. The ability to hear, see and speak properly, and physical good health, are all blessings.
Breathing is another of these blessings, and so on. The Sunnah does not say that we should prostrate for such blessings. But if we assume that a person was faced with difficulty in breathing, then Allah granted him relief from that, and he prostrated in gratitude to Allah, then he has done the right thing, because being able to breathe properly after having difficulty with it is a new blessing. 
Another example is if a person passes an exam when he was scared that he would not pass. This is a new blessing for which he should prostrate. 
Another example is if a person hears that the Muslims have attained a victory in any place. This is a new blessing for which he should prostrate to Allah in gratitude. 
Another example is if a person is blessed with a child. This is a new blessing for which he should prostrate. And you can draw more analogies.  
The words “and when adversity is warded off” refer to adversities for which the causes exist but one is spared. 
An example of that is a man who has a car accident when he is travelling, and the car turns over but he walks away unharmed. In this case he should do the prostration of gratitude, because the cause of this adversity was present, which is the car rolling over, but he was spared. 
Another example is a person in whose house a fire begins, but Allah makes it easy to extinguish it. This is warding off of adversity so he should prostrate to Allah in gratitude. 
Another example is a man who falls in a well and emerges safe and sound. This is warding off of adversity so he should prostrate to Allah in gratitude. 
What is meant by that is the warding off of an adversity the cause of which was present but he was spared it. As for those which are ongoing, they are innumerable, and if we were to tell a man that it is mustahabb to prostrate for ongoing blessings, he would always be prostrating. End quote. 
To sum up: the prostration of gratitude is to be done when a new blessing comes, not for ongoing blessings. 
And Allah knows best.