It is most likely to be due to posterior vitreous detachment ( PVD ).In this condition the thick gel at the back of the eye( called vitreous) gets detached from its surrounding retina . This results in retinal traction which results in the symptom of flashes of light and includes color distortion.Flashes of light may not be prominent in some individuals. Once the vitreous gets detached completely , it may form clumps or strands and cause symptom of floaters such as dark spots, cobweb or thread like strands in the visual field. Probably the vision of his own eyebrows and eyelashes is due to the clumped vitreous. More often it is not a serious issue and does not require any specific treatment. A routine retina examination needs to be done by an ophthalmologist just to check for the intactness of the retina and to look for any peripheral retinal tears or holes, which if found, can be sealed by lasers. The only concern is that of a remote possibility of a retinal tear extending into a frank retinal detachment, which is characterised by symptoms of sudden increase of flashes or floaters and a curtain or veil falling in the field of vision. This requires urgent treatment by a retinal specialist.This is not a common feature and is more predisposed in myopic and diabetic individuals.He does not seem to be having any of these acute symptoms, so as of now a routine eye exam should suffice. PVD can occur suddenly at anytime and is a diagnosis of exclusion and does not show any signs as such on eye examination. What he would need at this stage is a routine eye exam ( not an emergency) to look at the back of the eye. If PVD is confirmed then there is nothing much to be done. It would be best to ignore the floaters after that. Some floaters tend to drift out of visual field too.There can be other conditions also with similar floaters but would need a dilated eye exam for diagnosis.
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