I was reading from this Wikipedia article that the name of the centurion officer who pierced Jesus with a 3-foot pike on the left rib was Longinus and that his words "Truly this man was the son of God" were said after the blood and water coming out of the pierced rib cured him of his eye infection and that he later converted. Is this true?
The name is probably Latinized from the Greek lonche (λόγχη), the word used for the lance mentioned in John 19:34. 
 The name cannot be ascribed to any tradition; its obvious derivation from logchē (λόγχη), spear or lance, shows that it was, like that of Saint Veronica, fashioned to suit the event. — Elizabeth Jameson, The History of Our Lord as Exemplified in Works of Art
— Wikipedia, Longinus.
Further linguistic explanation: λόγχη would transliterate as logkhe, the g preceding a k or kh or g being usually read as an n, as in the Greek aggelos yielding the Latin angelus.
The cloth bearing an image of Jesus's face was known in Latin as the vera icon (true image), and this name for the relic was misinterpreted as the name of a saint.
— Wikipedia, Saint Veronica.
Is Longinus the name of the roman centurion who pierced Jesus?
The short answer is maybe?
According to tradition the answer is yes.
Now let me explain. Traditionally the name of the Roman soldier that pierced Christ’s side was Longinus.
Let us start with what the Gospel of St. John actually say about the situation.
But one of the soldiers with a spear opened his side, and immediately there came out blood and water. - John 19:34
Since the Gospels are silent on the name of the Roman soldier who pieced Jesus’ side, tradition and pius legends have come down to us that his name of Longinus.
Longinus is the name given to the unnamed Roman soldier who pierced the side of Jesus with a lance and who in medieval and some modern Christian traditions is described as a convert to Christianity. His name first appeared in the apocryphal Gospel of Nicodemus. The lance is called in Christianity the "Holy Lance" (lancea) and the story is related in the Gospel of John during the Crucifixion. This act is said to have created the last of the Five Holy Wounds of Christ.
This person, unnamed in the Gospels, is further identified in some versions of the legend as the centurion present at the Crucifixion, who said that Jesus was the son of God, so he is considered as the first Christian. Longinus' legend grew over the years to the point that he was said to have converted to Christianity after the Crucifixion, and he is traditionally venerated as a saint in the Roman Catholic Church, Eastern Orthodox Church, and several other Christian communions.
Origins of the story
No name for this soldier is given in the canonical Gospels; the name Longinus is instead found in the Acts of Pilate, a text appended to the apocryphal Gospel of Nicodemus. Longinus did not start out as a saint. An early tradition, found in a sixth or seventh century pseudepigraphal "Letter of Herod to Pilate", claims that Longinus suffered for having pierced Jesus, and that he was condemned to a cave where every night a lion came and mauled him until dawn, after which his body healed back to normal, in a pattern that would repeat till the end of time. Later traditions turned him into a Christian convert, but as Sabine Baring-Gould observed: "The name of Longinus was not known to the Greeks previous to the patriarch Germanus, in 715. It was introduced amongst the Westerns from the Apocryphal Gospel of Nicodemus. There is no reliable authority for the Acts and martyrdom of this saint."
The name is probably Latinized from the Greek lonche (λόγχη), the word used for the lance mentioned in John 19:34. It first appears lettered on an illumination of the Crucifixion beside the figure of the soldier holding a spear, written, perhaps contemporaneously, in horizontal Greek letters, LOGINOS (ΛΟΓΙΝΟϹ), in the Syriac gospel manuscript illuminated by a certain Rabulas in the year 586, in the Laurentian Library, Florence. The spear used is known as the Holy Lance, and more recently, especially in occult circles, as the "Spear of Destiny", which was revered at Jerusalem by the sixth century, although neither the centurion nor the name "Longinus" were invoked in any surviving report. As the "Lance of Longinus", the spear figures in the legends of the Holy Grail.
Blindness or other eye problems are not mentioned until after the tenth century. Petrus Comestor was one of the first to add an eyesight problem to the legend and his text can be translated as "blind", "dim-sighted" or "weak-sighted". The Golden Legend says that he saw celestial signs before conversion and that his eye problems might have been caused by illness or age. The touch of Jesus's blood cures his eye problem:
Christian legend has it that Longinus was a blind Roman centurion who thrust the spear into Christ's side at the crucifixion. Some of Jesus's blood fell upon his eyes and he was healed. Upon this miracle Longinus believed in Jesus.
The Gospels do not mention the Roman soldier’s name; they do not say it was the Roman centurion that pierced Our Lord’s side.
Traditionally the Church holds that St. Longinus, the soldier that pierced Our Lord’s side did convert and his feast day is March 25, the ancient piously believed day of the actual Crucifixion of Jesus Christ.
I have often wondered about this question matter over many years. In fact the legend of St. Longinus posed a few problems for me in my own personal way of thinking.
For one thing, tradition holds that St. Longinus was the centurion at Christ’s crucifixion. Having known that the by military standards of the times, the centurion would have been the only soldier seen on a horse and he would have allowed and ordered one of the other soldiers to administer the coup de grace, but would not have pierce a crucified himself. Thus, I personally believe that St. Longinus had to have been a regular foot soldier and not a centurion.
St. Longinus is the centurion who pierced the side of Our Lord while He was hanging on the Cross. St. Longinus, who was nearly blind, was healed when some of the blood and water from Jesus fell into his eyes. It was then he exclaimed "Indeed, this was the Son of God!" [Mark 15:39]. St. Longinus then converted, Left the army, took instruction from the apostles and became a monk in Cappadocia. There he was arrested for his faith, his teeth forced out and tongue cut off. However, St. Longinus miraculously continued to speak clearly and managed to destroy several idols in the presence of the governor. The governor, who was made blind by the demons that came from the idols, had his sight restored when St. Longinus was being beheaded, because his blood came in contact with the governors' eyes. St. Longinus' relics are now in the church of St Augustine, in Rome. His Lance is contained in one of the four pillars over the altar in the Basilica of St Peter's in Rome. - St. Longinus (Catholic Encyclopædia)
Interestingly, Blessed Anne Catherine Emmerich in her revelations actually names Abenadar as the centurion at Jesus’ Crucifixion. He converted and became a saint also.
On the 1st of April 1823, Sister Emmerich said that that day was the Feast of St. Ctesiphon, the centurion who had assisted at the Crucifixion, and that she had seen during the night various particulars concerning his, life. But she had also suffered greatly, which, combined with exterior distractions, had caused her to forget the greatest part of what she had seen. She related what follows:
Abenadar, afterwards called Ctesiphon, was born in a country situated between Babylon and Egypt in Arabia Felix, to the right of the spot where Job dwelt during the latter half of his life. A certain number of square houses, with flat roofs, were built there on a slight ascent. There were many small trees growing on this spot, and incense and balm were gathered there. I have been in Abenadar's house, which was large and spacious, as might be expected of a rich man's house, but it was also very low. All these houses were built in this manner, perhaps on account of the wind, because they were much exposed. Abenadar had joined the garrison of the fortress Antonia, at Jerusalem, as a volunteer. He had entered the Roman service for the purpose of enjoying more facilities in his study of the fine arts, for he was a learned man. His character was firm, his figure short and thick-set, and his complexion dark.
Abenadar was early convinced, by the doctrine which he heard Jesus preach, and by a miracle which he saw him work, that salvation was to be found among the Jews, and he had submitted to the law of Moses. Although not yet a disciple of our Lord, he bore him no ill-will, and held his person in secret veneration. He was naturally grave and composed, and when he came to Golgotha to relieve guard, he kept order on all sides, and forced everybody to behave at least with common decency, down to the moment when truth triumphed over him, and he rendered public testimony to the Divinity of Jesus. Being a rich man, and a volunteer, he had no difficulty in resigning his post at once. He assisted at the descent from the Cross and the burial of our Lord, which put him into familiar connection with the friends of Jesus, and after the day of Pentecost he was one of the first to receive baptism in the Pool of Bethsaida, when he took the name of Ctesiphon. He had a brother living in Arabia, to whom he related the miracles he had beheld, and who was thus called to the path of salvation, came to Jerusalem, was baptised by the name of Caecilius, and was charged, together with Ctesiphon, to assist the deacons in the newly-formed Christian community.
Ctesiphon accompanied the Apostle St. James the Greater into Spain, and also returned with him. After a time, he was again sent into Spain by the Apostles, and carried there the body of St. James, who had been martyred at Jerusalem. He was made a bishop, and resided chiefly in a sort of island or peninsula at no great distance from France, which he also visited, and where he made some disciples. The name of the place where he lived was rather like Vergui, and it was afterwards laid waste by an inundation. I do not remember that Ctesiphon was ever martyred. He wrote several books containing details concerning the Passion of Christ; but there have been some books falsely attributed to him, and others, which were really from his pen, ascribed to different writers. Rome has since rejected these books, the greatest part of which were apocryphal, but which nevertheless did contain some few things really from his pen. One of the guards of our Lord's sepulchre, who would not let himself be bribed by the Jews, was his fellow countryman and friend. His name was something like Sulei or Suleii. After being detained some time in prison, he retired into a cavern of Mount Sinai, where he lived seven years. God bestowed many special graces upon this man, and he wrote some very learned books in the style of Denis the Areopagite, Another writer made use of his works, and in this manner some extracts from them have come down to us. Everything concerning these facts was made known to me, as well as the name of the book, but I have forgotten it. This countryman of Ctesiphon afterwards followed him into Spain. Among the companions of Ctesiphon in that country were his brother Caecilius, and some other men, whose names were Intalecius, Hesicius, and Euphrasius. Another Arab, called Sulima, was converted in the very early days of the Church, and a fellow countryman of Ctesiphon, with a name like Sulensis, became a Christian later, in the time of the deacons.
St. Ctesiphon (Abenadar) in any case is considered a saint. Whatever his true historical circumstances were, he is definitively a first century saint. St. Ctesiphon is one of the Seven Apostolic Men in Spain!
Saint Ctesiphon or Ctesiphon of Vergium is venerated as patron saint of Berja, Andalusia, southern Spain. Tradition makes him a Christian missionary of the 1st century, during the Apostolic Age. He evangelized the town of Bergi, Vergi(s), or Vergium, identified as Berja, and is said to have become its first bishop, but the Diocese of Vergi was probably only founded around 500.
Ctesiphon's relics purportedly lie in the catacombs of Sacromonte Abbey in Granada, along with those of Hesychius of Cazorla and Caecilius of Elvira. - Seven Apostolic Men
According to Catherine Emmerich, Cassius, who, when he became a Christian, was known by the name of Longinus.
As soon as the executioners had crucified the two thieves and divided the garment of Jesus between them, they gathered up their tools, addressed a few more insulting words to our Lord, and went away. The Pharisees, likewise, rode up to Jesus, looked at him scornfully, made use of some opprobrious expression, and then left the place. The Roman soldiers, of whom a hundred had been posted round Calvary, were marched away, and their places filled by fifty others, the command of whom was given to Abenadar, an Arab by birth, who afterwards took the name of Ctesiphon in baptism; and the second in command was Cassius, who, when he became a Christian, was known by the name of Longinus: Pilate frequently made use of him as a messenger. Twelve Pharisees, twelve Sadducees, as many scribes, and a few ancients, accompanied by those Jews who had been endeavouring to persuade Pilate to change the inscription on the Cross of Jesus, then came up: they were furious, as the Roman governor had given them a direct refusal. They rode round the platform, and drove away the Blessed Virgin, whom St. John led to the holy women. When they passed the Cross of Jesus, they shook their heads disdainfully at him, exclaiming at the same time, 'Vah! thou that destroyest the temple of God, and in three days buildest it up again, save thyself, coming down from the Cross. Let Christ, the King of Israel, come down now from the Cross, that we may see and believe.' The soldiers, likewise, made use of deriding language. - First Word of Jesus on the Cross.
There does seem to be some hope the several of Jesus’ executioners May have converted, but facts are lost to history.
Abenadar the Centurion, an Arab by birth, and a disciple baptized later on at Ctesiphon, had, since the moment in which he had given Jesus the vinegar to drink, remained seated on his horse close to the eminence upon which the cross was raised, the forefeet the animal planted near it and, consequently, higher than the hind feet. Deeply affected, he gazed long, earnestly and fixedly into the thorn-crowned countenance of Jesus. The horse hung his head as if in fear, and Abenadar, whose pride was humbled, let the reins hang loose. When the Lord in a clear, strong voice uttered those last words, when He died with that loud cry that rang through Heaven, earth, and Hell, the earth quaked and the rock between Him and the thief on His left was rent asunder with a crashing sound. That loud cry, that witness of God, resounded like a warning, arousing terror and shuddering in mourning nature. It was consummated! The soul of Our Lord had left the body! The death cry of the dying Redeemer had roused all that heard it; even the earth, by its undulations, seemed to recognize the Saviour, and a sharp sword of sorrow pierced the hearts of those that loved Him. Then it was that grace penetrated the soul of Abenadar. The horse trembled under his rider, who was reeling with emotion; then it was that grace conquered that proud mind, hard as the rock of Calvary. He threw his lance to the ground and, with his great clenched fist, struck his breast vigorous blows, crying aloud in the voice of a changed man: "Blessed be God the Almighty, the God of Abraham and Jacob! This was a just Man! Truly, He is the Son of God!" And many of the soldiers, deeply affected by his words, followed his example.
Abenadar, who was now a changed being, a man redeemed, after his public homage to the Son of God would no longer remain in the service of His enemies, He turned his horse toward Cassius, the subaltern officer, known under the name of Longinus, dismounted, picked up his lance, presented it to him and addressed a few words both to him and the soldiers. Cassius mounted the horse and assumed the command. Abenadar next hurried down Mount Calvary and through the Valley of Gihon to the caves in the Valley of Hinnom, where he announced to the disciples hidden therein the death of the Lord, after which he hastened into the city and went straight to Pilate.
Abenadar rendered public testimony to his belief in Jesus, and his example was followed by many of the soldiers. Numbers of those present, and some of the Pharisees last come to the scene, were converted. Many struck their breast, wept, and returned home, while others rent their garments and sprinkled their head with dust. All were filled with fear and dread. - The Death of Jesus. - Fifth, Sixth, and Seventh Words on the Cross