Take home message:  your retinal cells are light communicators. They can't process pain (other parts of your eye can, but not your retinal cells!), so a retinal tear is as painless as a normal floater.  If you are seeing spots of lights, there may be a simple explanation that has nothing to do with your actual eye, just because the eye only can speak 1 language: light.  If you ever see flashing lights followed by vision loss, or a swarm of new floaters all at once, it is best to be seen by a doctor just in case it is a retinal detachment.  The only way to make sure your symptoms are normal is to have your eye dilated and checked by a professional.

The 18 year old football player whose brain was found to have Alzheimer's type misfolded proteins in his brain after suffering multiple concussions on the field is still on my mind.  See this post for the link.  As an optometrist, I do see patients from time to time that have suffered concussions.  Typically they are getting to my office several weeks to months later, so I am treating the more long-term side effects.  There are ocular sequelae to concussions that patients and new ODs should be aware of, so here is a break down of the most common things I encounter.

Headaches and blurry vision when reading is something that patients may experience even months after their concussion.  I recently saw a 16 year old that had suffered a concussion two months earlier playing soccer, and she was only starting to return to heavy duty reading.  After a few minutes of near work her eyes felt tired, strained, and she complained of blurry vision.  Before her concussion she had never worn glasses, and never had any problems with distance or near vision.  We did a thorough near work-up, and she needed +1.00 reading glasses to reduce her reading strain.  The focusing system is one of the primary functions impacted after head injuries, so definitely ask your concussion patients if they are having problems with near strain.  They may need reading glasses and/or vision therapy as they continue to recover!

Immediately after a concussion there will definitely be pupil abnormalities, but pupil differences can persist for a short time afterwards.  If one eye's pupil is a different size than the other (called anisocoria), the eye with the larger pupil will experience: 

Here's a case I recently had:  A few months ago I saw a patient with sudden onset floaters in her right eye.  She was experiencing no flashes of light and no vision change.  A few floaters were seen upon dilation, but she had no retinal breaks and no signs of a posterior vitreal detachment (all medical findings that are associated with new floaters).  When she came back a few weeks later for follow-up, the floaters were persisting, but again there were no ocular findings.  Another month later I checked her again, and she reported improvement in the appearance of floaters (and again no ocular findings).  She recalled that the day before she called in with floater complaints for the first time she had fallen in the attic and hit her head very hard.  Floaters, headaches, and migraines with visual auras can definitely be associated with head injuries, but of course, so can retinal tears and detachments.  The 3 signs to look for are: