Feeling dizzy while looking at iPhone and laptop?

Two days ago I was on my laptop, iPhone, and TV. I started feeling horribly dizzy so I stopped and didn't use my phone or laptop just the tv the next day. Today I use my iPhone again and I'm starting to feel a bit dizzy again. My eyes also hurt when I move them around. What could be causing this?

How to enable 'take photo' function on selfie stick?

I bought a selfie stick at Staples and it said you needed to enable take photo function in settings. I have an iPhone 5s. I can' t find any take photo function in Settings and the shutter button won't work. Is it broken?

Which one of these sentences is correct?

IPhone has never been number one or iPhone had never been number one?

Added (1). Here's the context: I'm trying to say iPhone [.] never been the number one for me to look for when buying a new mobile phone.

I bought an iPhone 4 but i don't know if I should keep it?

I thought I had to return my iPhone 5 back to Verizon so I bought an iPhone 4 just so I could get buy and then buy the 6 but it turns out I don't need to return my iPhone and I'm wondering if I should keep it just in case, sell it, or return it?

Does the iPhone 6 charger work for an iPhone 5c?

I have an iPhone 5c and I got another charger but I read the package as soon as I got it and it said it is an iPhone 6 charger. But can an iPhone 6 charger work on an iPhone 5c? The charger I'm currently using is developing a small turtleneck so I need to know quickly.

Can the iPhone 6 front camera autofocus?

I'm starting a YouTube soon and would like to vlog with the iPhone, IIm wondering if the front camera can autofocus and make the background blurry, IIm currently on my grandpa s iPhone 4 with iOS 7 and I notice that only the back camera has autofocus, HDR and flash but not the front