Everyone sees a few tiny floaters. These become more obvious when staring at a uniform white surface. If one looks up at the ski you might see these spots moving around. You are seeing the blood flow through the tiny blood vessels. These are of no concern.
However, a sudden onset of floaters particularly associated with flashes of light warrants an immediate eye exam. Most of the time our examination reveals that these spots, cob-webs, and lines are vitreous particles that have separated from the retina and are forming a shadow on the retina. Unfortunately, in small percentage of people who experience flashes and floaters, there is a vitreous detachment with an associated tear in the retina. If the vitreous collapses but does not separate completely from the retina, the vitreous via traction can tear the retina. If the vitreous separates from the retina, it will snap back and probably seal itself. However, if it doesn't separate from the retina it can continue to pull the retina from the back of the eye. This is known as a retinal detachment and is very serious.
Unfortunately, we can not differentiate the more benign vitreous detachment or degeneration without retinal involvement from the vitreous detachment with retinal detachment without performing a comprehensive dilated examination of the retina. Thus, if you have these symptoms you must be examined immediately and the retina needs to be re-attached immediately. The longer the retina is separated from the eye the less the chance of restoring vision upon re-attachment.
Flashes are produced by the traction of the vitreous on the retina, need to be differentiated from the flashes that occur with migraines. Migraine flashes are present in both eyes and tend to move through the visual fields. Flashes from vitreous traction are found only in one eye and do not move very much. Flashes are not nearly as much of a concern as the floaters.
If there is no retinal hole, tear or detachment associated with the vitreous detachment one should be careful for the next six weeks. No heavy lifting or picking should be allowed. Any increase in spots should result in a repeat retinal evaluation. In any case a repeat examination should be performed in twelve weeks.
Myopic patients particularly in the mid-range (4-8D) are the most prone to retinal detachments. Dilated examination of the peripheral retina is important on a routine basis to determine if there are any weak areas of the retina. Remember, LASIK re-sculptures the cornea it does not effect the back of the eye. Thus, patients who are no longer nearsighted due to LASIK are just as prone to retinal problems as their fellow non-LASIK friends.