Some of us have good eyesight and some are blind, some short and some tall, some (physically) beautiful some not, some knowledgeable and some ignorant, some wealthy and some poor, some with defective bodies and some free of bodily defects… See what Allah (swt) has to say when Adam (as) questions Him (swt) about this.

“I heard abu Ja’far (as) say: ‘There was a time when Allah, the Majestic, the Glorious, took the descendents of Adam from his back to establish a covenant with them to testify that He is their Lord and to believe in the prophethood of all the prophets. The first among the prophets whose prophethood Allah wanted them to accept through a covenant was Muhammad ibn ‘Abd Allah (sawa).
Allah, the Majestic, the Glorious, then said to Adam, “Look (to find) what you can see.” ‘The Imam then said, “Adam then looked and saw his descendents appearing as small particles that filled the sky. Adam then said, ‘Lord, how huge in number my descendents are! For what purpose have You created them and for what reason did You make them to establish a covenant with You?’” Allah, the Majestic, the Glorious, replied, “So that they worship Me and do not consider anything else as My equal and so that they believe in My messengers and follow them (for guidance).”
Adam then asked, “Lord, why is it that I see certain ones of the particles are greater, others have a great deal of lights, yet others among them have very little light and still others among them have no lights at all?” Allah, the Majestic, the Glorious, replied, “Thus, I have created them to place them to test in every condition that they will live.” Adam then asked, “My Lord, will You grant me permission to speak so I may express myself?” Allah, the Majestic the Glorious said, “Speak up; your spirit is from My spirit but your nature is different from My being.”
Adam then asked, “Lord, had You created them all just like each other, by the same measure, the same nature, of likewise design, of the same color, of equal life span, of equal amount of means of living they would not act against each other. No jealousy, animosity and differences would exist among them over anything.”
Allah, the Majestic, the Glorious, said, “O Adam, through My spirit you just spoke and due to the weakness of your nature you made an effort to give an opinion about that of which you have no knowledge. I Am the Creator of the world. I knowingly have created each one different from the others and through My Own way I will make My commands to take effect and they will continue existing through My plans and measures. There will be no changes in My creation. I have created the Jinn and human beings only to worship Me. I have created paradise for those who obey and worship Me and follow My messengers. I have no regrets in what I have done. I have created the fire for those who disbelieve, disobey Me and do not follow My messengers and I have no regrets in it. I have created you and your descendents not because I ever need you or your descendents in anyway or form. I have created you and created them to test you and test them to see which ones among you do good deeds in the worldly life before your deaths. For this reason I have created the world and the life thereafter, life, death, obedience, disobedience, paradise and the fire. This is how I willed in My measure and plan. Through My all-pervasive knowledge in them I have placed differences in their forms, bodies, colors, lifespan, means of living, obedience and disobedience. I, thus, have made certain ones of them to be unfortunate or very fortunate. Certain ones among them will have eyesight or be blind, others among them will be of short size or tall ones, beautiful or otherwise, knowledgeable or ignorant, wealthy or poor, obedient or disobedient, of good health or suffering from illness, of defective bodies or free of bodily defects. In this way those of perfect bodies will look at the defective ones and thank Me for the perfect body that I have given them and those with defective bodies will look at the perfect ones and will pray to Me and ask Me to grant them good health and exercise patience when and in the way I test them. Thus, I will grant them good rewards. The wealthy ones after looking to the poor ones will thank Me and appreciate My favors. When the poor ones look to the wealthy ones they pray to Me and ask Me favors. It is as such so that the believers will look to the unbelievers and thank Me for the guidance that I have granted them. For such reasons I have created them. I test them in ease and in hardships and in good health that I grant them and in the matters with which I test them, in the matters of what I grant them and in the matters that I refuse them. I am Allah, the powerful King. It is all up to Me to allow all of My measures and plans to take form or change them as I wish to the time that I wish. I may change the sequel of the timing of my measures and plans and allow, that which comes first to come last and vice versa. I am Allah, and I execute whatever I will. I am not questioned for whatever I do but I question My creatures about their deeds.”’”

Sanad: Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad and Ali ibn Ibrahim has narrated from his father from al-Hassan ibn Mahbub from Hisham ibn Salim from Habib al-Sajistani who has said the above hadith

Source: Usool al-Kafi, Volume 2, Chapter 3, Hadith #2 (See First Image below)

Grading: Allaamah al-Majlisi graded this hadith having a Good (حسن) chain [Mira’at al-Uqool, Volume 7, Page 24 (See Second Image below)]