You are not alone.
All doctor visits make me anxious, but the eye doctor held a special place. I was diagnosed with ocular hypertension (pre-glaucoma) at age 25 and was sent to specialists in NYC to see why I would have eye pressure of 21 at age 25. Doctors all read me the riot act, that I would need to be on eye drops for life and that I may lose peripheral vision at an early age if not vigorously treated. 32 years later and still no optic nerve damage or loss of vision and eye pressure still in the mid 20's with no medication whatsoever. It turns out the device they use to test eye pressure does not take into account the thickness of your cornea and people with a thick cornea show a high eye pressure. All these years I have feared every eye doctor appointment (at one point every 3 months) sure they would find damage and loss of vision and it turns out my eye pressure is normal for a person, like me (and my sister) with a thick cornea.
I also recently switched eye doctors from a rushed and abrupt doctor to a kind and gentle female ophthalmologist in the same practice. She reduced my anxiety level to a tolerable level just due to her calm demeanor. With regard to your initial question, she said that the picture of your retina thing that you hate (and gives me strange vision for several minutes as well) is not necessary every visit. I get the feeling this is a new expensive device and they use it on everyone with insurance so they can make the payments on the machine. So, ask if you really need to have that test done as it may not be necessary.
The test I really hate is the field of vision test where they put your head in a box and you have to look straight ahead for about 20 minutes trying not to blink (which is nearly impossible) and push a button every time a small light appears. I would take the retina picture over field of vision test any day.