An example of one of these devices is a column chromatography bed, meaning that the stationary bed is in a tube. In some situations, chromatography is used as a method of purification. This is referred to as preparative chromatography. Another use of chromatography is analytical chromatography. This method of separation occurs with smaller amounts of material and is used to measure analytes in a mixture.
Flashing lights and floaters may be the initial symptoms of a retinal detachment or of a retinal tear that precedes the detachment itself. Anyone who is beginning to experience these symptoms should see an eye doctor (ophthalmologist) for a retinal exam.
It is important to keep in mind however, that the field of retina has changed dramatically over the past two decades and continues to evolve very rapidly. Even for a full-time retinal specialist, it is challenging to stay abreast of the newest developments in therapy. Optometrists do not typically provide treatment for retinal diseases. General ophthalmologists may choose to provide treatment for some conditions (for example, diabetic retinopathy).