Microgravity affects vision. 

A mysterious syndrome has been impairing astronauts’ vision on the International Space Station, causing untreatable nearsightedness that lingers for months even after they’ve returned to Earth. The problem is so bad that two-thirds of astronauts report having deteriorated eyesight after spending time in orbit. Now scientists say they finally have some answers – and it’s not looking good for our prospects of getting to Mars. “Nobody’s gone two years with exposure to this, and the concern is that we’d have loss of vision,” Dorit Donoviel from the US National Space Biomedical Research Institute told The Guardian. “That is catastrophic for an astronaut.” 

Earlier this year, NASA reported that something in space has been messing with its astronauts’ perfect eyesight, causing long-term impairment to their quality of vision. Astronaut Scott Kelly, whose exceptional vision was part of the reason he was selected to be America’s first astronaut to spend a full year in space, says he’s been forced to wear reading glasses since coming home. John Phillips, who spent time on the International Space Station (ISS) in 2005, brought his sudden bouts of blurry vision home with him, and during his post-flight physical, NASA confirmed that his vision had gone from 20/20 to 20/100 in just six months. NASA suspected that the condition – called visual impairment inter cranial pressure syndrome, or VIIP – was caused by the lack of gravity in space. 
Science Alert, Space Could Leave You Blind, And Scientists Say They’ve Finally Figured Out Why, 2016

Most astronauts feel dizziness and nausea in the first few days in space but blurred vision seems to be more lasting.

But 1400 years ago the Quran said that if Allah opens a wormhole for you in space you will think your vision is intoxicated:

[Quran 15.14-15] Even if We [Allah] opened upon them from the heaven a door and they continued passing through it they would say ‘Our sight is intoxicated (سُكِّرَتْ ), rather we have been bewitched‘.

Sukkirat in Arabic “سُكِّرَتْ ” means gotten drunk. Dizziness, nausea and blurred vision are common symptoms of getting drunk. Today we know that astronauts experience dizziness, nausea and blurred vision.

How could an illiterate man who lived 1400 years ago have known about the effects of microgravity on vision?