Our eyes are taking 10 pictures per second. So on a daily basis, the eyes are constantly taking 576,000 pictures if a person sleeps for 8 hours. Which camera can continue to function for years and years without being electronically charged like the eyes? Indeed, the creations of Allah are something to think about.
In addition, an average eye blinks 12 times a minute. That's an amazing 11,520 blinks a day if a person sleeps for 8 hours. There are diseases which prevent a person from blinking by causing the eye lids not to open or close. The people suffering from such diseases truly understand the value of blinking.
"He it is Who brought you into being and made for you the ears and the eyes and the hearts: little is it that you give thanks." (The Qur'an, 67:23)