@Background Pony #04BD  
Maybe that’s why she lost the gold status. Her vision got worse.

@Korora
 
Yeah, fans noticed it the second the scene happened and commented on the live chats.
 
And then there were these made shortly after the episode aired.
 
 

@ambient nightfall  
Right off the bat. While it’s less of a problem than it would be for a human (and only looks otherwise because of the stylization of the art), horses do have sixty-five degrees of binocular vision directly forward–where it is important in a race.
 
BTW, on one of the Reflections covers, Evil!Derpy has prism lenses.

Has no one else noticed Derpy’s eyes are fine then she slowly goes downhill and they cross with each time pass?

My assumption with them being around the same age is they went through the proper channels to become Wonderbolts; like they as soon as they were old enough they applied to the academy, got in and worked themselves up in rank.
 
Meanwhile Dash finds herself kicking clouds in an earth pony town where her old friend lives now. I remember a popular fanon in the day was that Dash dropped out of school to stay close to Fluttershy/was kicked out. Yet she still has her dream to become a Wonderbolt. She knows if she makes a name for herself she could become a member. Seasons later, she’s famous but realizes (or is told) she has to literally apply to the academy like everyone else; her fame isn’t enough to cover her lack of education. Since there’s so much more to it than being awesome.
 
So Dash reaches her dreams but nearly takes the long way around.

@Background Pony #C0CE  
Added the appropriate tags.

All these filly’s are so cute

When Dashie moved to Ponyville, she probably recognized Derpy as “that filly from Flight Camp whose eyes started giving her trouble”. Lightning Dust was certainly not a close friend at the time–Gilda was–and Cloudsdale has to be a big city (and Lightning Dust may not even be from Cloudsdale).

Wow so Lighting Dust and Rainbow Dash actually have had history before they became rivals

Lightning Dust was mostly faster than anyone here in  
this, but she was the best of all of them.

@Master Fox  
That’s one reason I don’t take this flashback scene too seriously.
 
@BlueStreak  

Pretty much, but I also suspect DHX thought we’d just like to see these ponies as fillies. And I did find it amusing, even if it means I can’t take this flashback too seriously.

@Ferrotter  
Well, those few times since this is the progression of several competitions but yes, exactly.

@FoldabotZ  
Or it’s an athletic event and they’ve only met each other that one time.

@BlueStreak  
Not necessarily, they could be like the type of people (or ponies in this case) who went to the same Kindergarten but didn’t really know each other and only became friends when they met up again as adults.

I’d always assumed these ponies are familiar faces merely because the show didn’t want to make eight new ones for one scene they’re in Dash’s recent memory and they just serve as placeholders. There’s no other way it’d make sense; otherwise, they all would have KNOWN each other long before their early season appearances.

@Background Pony #4014  
Yet she never stops smiling. She’s such a trooper.

Well fuck… I always thought Spitfire was older than Rainbow

@Master Fox  
Dash did mention she was the youngest there, but only by a year or so. I’m OK with Spitfire/Soarin’ being just slightly older. I always felt that people made Soarin’ too old.

@Master Fox  
Yeah me too… Maybe they’re still old enough to be considered a filly/colt, but very close to being able to be considered a mare/stallion, but Rainbow Dash is still considered a filly and won’t be considered a mare for a while.

@Red Cedar Yes… #derpyisbestpony

Our poor little grey angel…

I always thought Soarin and Spitfire would be older then dash. Maybe not a lot but enough that they would be her superiors in rank. I mean Dash was still considered eligible for the Best Young Flyer competition in the first season yet the other two where already Wonderbolts in full. Spitfire already the poster child.

@Background Pony #4014 Yeah it is kind of sad
 
 
@Background Pony #E258 IKR? I’m glad we got to see her again, though, even if it was just a flashback. We hadn’t seen her since Wonderbolts Academy.
 

 
@TJPones Same :)

@TJPones  
Also how Lightning Dust is unhappy the instant she’s not at the very top.

Derpy’s eyes are relatively normal at the start, her rank went down as her eyes got worse. That’s kind of sad