"Do they cover up the other lines when you're reading one?"
No, the lines are shown all at once on the wall.
"Also, do you cover up your one eye with your hand or do they give you something?"
They give you a black plastic spoon-looking device to cover one eye with.
"i hear there are like 4 charts."
I know there are at least 2 different charts. If you are thinking about memorizing the charts you will have to have an extremely good memory to pull that off. Even if you did, they will nail you with the occular exam. There is no way to fake that. hehe Plus, I have never seen charts like the ones they use. They are a good 12 letters across for each line. After ten years of being a Hospital Corpsman, I have never seen the charts they use in any optometry facility in any other military hospital.
"Do they move the charts around?"
I'm not sure if you are asking if the charts are moved around during the exam or between each person they examine. I took two different eye exams, once in OCS and again in API to confirm my eyesight. The charts seemed to be the same both times I took it.
"Is it projected against a wall or is it behind a translucent film?"
They are projected on the wall.
"Do they give you much time or do they rush you through?"
They let you take your time. They know that your eye exam can be the make or break point in what you are eligible to do. They won't give you 5 minutes for each letter...but they will allow you to take a bit of time to get the letters you are able to see.
"Was it an officer that gave the exam or an enlisted?"
The initial screening is done by one of the optometry techs, an enlisted person or a civilian. All they do is test your vision with and without glasses (if you wear them). They also test you for color blindness and they give you the occular tension test that consists of air being buffed into your eyes.
When they finish the initial screening you are then handed over to the actual optometrist, which is a naval officer. They will look inside your eyes to see if there are any problems going on in there. They also give you another visual acuity test. If they find that you cannot read the 20/20 with each eye, they will use their eye calibration machine to determine your eyeglass prescription.
Now, this is the tricky part. The guidelines say that you have to have 20/40 vision, or better, in each eye uncorrected to be a pilot. If you are something like 20/70 in one eye, you would normally fail to see the letters on the 20/40 line. What you can do is ask the optometrist let you read the 20/20 line with their machine set to 20/40. This isn't a widely known bit of info. My right eye bounces around from 20/30 to 20/70 and my left eye is 20/20. The optometrist allowed me to try and read the 20/20 line with the machine set to 20/40. The rules say that you have to have 20/40 or better in each eye. Since I was able to read the 20/20 line with the machine set to 20/40 I passed the test with my right eye...*barely*.
Even so, if you have an astigmatism greater than -1.00, you will not get the nod for pilot training. I was able to pass every other single test, but I have a -1.75 in my right eye. There is not way to fake that. They use that prescription machine to test for that and if you are outside of the -1.00 limitation, then you are outside of the maximum parameters. Even if you were -1.25, that is too much and you will not qualify for pilot.
The reason why they are so strict is because jet pilots tend to get worse vision after years of flying, or so this is what the optomretists told me at NAMI. The parameters are set up this way so that as the pilots age and their eyes change they will still be able to fly the plane in the event they somehow lose their glasses in flight. Also, they have done tests to determine reaction time for catching the trap on the deck of a carrier. The tests have consistantly shown that those with worse eye vision (even if they are corrected to 20/15) have lower visual reaction time if they wear glasses than those who naturally have 20/20 vision of better.
Now, if you make it through NAMI with a good eye exam, and you are selected for pilot, then you are good to go pretty much for the rest of your career. You can hit API with a 20/20 uncorrected visual acuity and then three months later somehow end up with 20/100 uncorrected visual acuity and you will still be eligible to be a pilot, so long as you are correctable to 20/20. Hell, even the day after your preliminary eye exam that said you had 20/40 vision in both eyes uncorrected, and then the very next day had 20/70 vision uncorrected, you'd still be ok to be a pilot. It all depends on that initial NAMI eye exam. Make it through that and you'll be ok from there on.
That is what bugged me about my own eye exam. I was shooting for pilot. I have 20/20 in my left and 20/40 in my right. I am correctable to 20/12 in both eyes. They let pilots fly with up to 20/200 uncorrected vision, so long as they are correctable to 20/20 or better in both eyes. If it wasn't for my astigmatism, I'd be in pilot training right now.
Everything depends on that preliminary NAMI eye exam. Just hope that you can hit the 20/40 lines without any problems and that you are within limits if you have an astigmatism. And if you are thinking about using a specific liquid that helps strengthen your visual acuity for a short duration...don't. The optometrists can see that when they look into your eyes during the exam and you'd probably get in huge trouble for being dishonest, especially as an officer where honor is paramount.
Good luck.
"The object of war is not to die for your country but to make the other bastard die for his." - General George Patton (1885-1945)