Have you ever seen little specks floating around in your vision while you’re staring at a plain background (like a blank page or blue sky), and no matter how much you blink these small shadow-like small things still remain in front of your eyes? These annoying shadows are so-called “floaters”. They move as your eyes move; however, since floaters move in the opposite direction of the eye, you usually cannot follow them by your eyes.
What are eye floaters?
Floaters are, in fact, shadows of turbidity in the vitreous fluid that falls on the retina and is seen as a dark shadow. These turbidities may be due to the adhesion and thickening of the vitreous tissue, the accumulation of inflammatory cells in the vitreous, or the intraocular hemorrhage.
What is vitreous?
Vitreous is a clear jelly-like fluid resembling raw egg white that fills most of the eyeball space (the space between the lens and the retina) and helps the preservation of spherical structure of the eye and keeps retina in place. The vitreous structure is made up of a spongy net composed of very delicate strands. This net contains plenty of water and soluble materials that give it a gelatinous form. Tissue strands in the vitreous are denser in the outer parts of the vitreous, and have relatively strong connections to the retina's inner layers.
What causes eye floaters?
Floaters are very common symptom and are more likely to occur with age, so it is estimated that more than 70 to 60% of people over 60 have experienced floaters.
Vitreous strands are very delicate and invisible in children and young adults, but as we age they thicken, get stringy and clump. These stringy entities float around the rest of the vitreous, casting shadows on the retina that are seen as floaters. Moreover, in most of the elderly people pieces of vitreous gel that is attached to the retina separate and fall into the central vitreous. This condition, which is called posterior vitreous detachment, is the main reason of floaters.Sometimes, the intraocular inflammation (uveitis) causes the accumulation of inflammatory cells in the vitreous which leads to floaters. Another cause of floaters is vitreous hemorrhage; for example, people with diabetes may have mild intraocular bleeding which at first may seem as a floater.
Who is more at risk of floaters?
• Those who are over 60 years
• Nearsighted people
• People who have a history of eye surgeries (cataract surgery in particular)
• People who have had uveitis
What are flashes?
In ophthalmology,flash means feeling spark of light in the visual field when in fact there is no optical stimulator. Flashes may appear as brilliant lines of lightning or as tiny luminous objects.Flashes may only be seen in a specific spot on the visual field or in the form of multiple small points in the visual field.The feeling of seeing flashes usually last for only a few seconds, but it often repeats. They usually appear more in dark environments. In addition, sudden movements of the head or eyes may cause flashes.
What causes flashes?
As it is told before, when we age, the vitreous strands get thicker and stickier. This stickiness can tug on the retina and pull away from it. Since the light entering the eye stimulates the retina, any factor that stimulates the cells of the retina is interpreted in the brain as light. Therefore, when the retina is under traction,flashes of light are seen.
Are floaters and flashes dangerous?
Many people have had floaters for many years and nothing particular has happened. Floaters that have been around for many years and have not had any special changes are usually not a threat, but the appearance of new floaters can be a sign of serious ocular problems. Of course, as it is told before, the most common reason of new floaters is posterior vitreous detachment. While that is harmless in itself, sometimes vitreous tugs on retina and causes retinal breakage or tear which may cause to retinal detachment and severe visual complications.
As it is mentioned, flashes are often caused by retina stimulation or traction; therefore there is a possibility of retinal tear in people who recently see flashes. It is not possible to detect the cause of flashes and floaters without proper ophthalmic examination. Therefore, it is imperative that all people who have seen flashes or found new floaters should be examined by an ophthalmologist. First, the eye pupil is dilated with special eye drops and then vitreous and retina are examined using lenses and special tools. If throughout the examination no problem is detected (aside from posterior vitreous detachment) and the retina is healthy, there is usually no danger and no special action is required. In cases where the retina is damaged or there is intraocular hemorrhage or inflammation, immediate treatment is necessary. Sometimes, the exact cause of the floaters cannot be detected in one examination turn.
In this case, it is usually necessary to repeat the examination at intervals of 3 to 2 weeks, until we make sure there is no dangerous cause.
It is very important to note that flashes, even if accompanied by retinal detachment, usually disappear after a few days to several weeks; floaters, even in the event of a retinal detachment, become smaller after a few weeks. Therefore, in patients who have recently seen flashes or new floaters, even if they are cured spontaneously, a full eye examination is required.
Are there any cure for flashes and/or floaters
As already mentioned, floaters usually do not have a dangerous cause and do not require treatment. In most cases, after a few weeks to a few months, the floaters gradually become smaller, and the person gets accustomed to ignore them. However, in cases of floaters caused by retinal hole or tear, it may be necessary to take therapeutic measures, such as laser or surgery, to prevent retinal detachment.
Flashes also go away after a few days to several weeks, and if there is no risk, they do not require treatment
Non-ocular reasons for flashes
People who have migraines often experience another type of flashes. These sparks are seen as shimmering lacing lines or flashing points. Usually, these flashes appear first in the middle of the visual field (i.e., in front of the person), and within 15 to 20 minutes move to the sides of vision field, and gradually disappear. After that, the headache starts which is usually one-way and pulsating. Of course, some people just see sparks and headache does not happen. This is called "eye migraine". An important point is that flashes caused by migraines are seen simultaneously in both eyes, but the flashes caused by eye problems appear only in the affected eye.
Another cause of flashes is a sudden blow to the head. Any sudden blow to the head may cause the person to see small bright sparkles for a few seconds.
As it has been said, old floaters that have existed for many years and have not particularly changed are usually safe. But in the following cases you have to consult an ophthalmologist as soon as possible:
• Newly appeared floater (even if it has gone away spontaneously after a few weeks)
• Old floaters that have recently become larger or have changed.
• Floaters together with flashes (even if after a few days flashes have gone away spontaneously)
• Floaters together blurry or reduced vision or feeling as if there is a curtain in front of the eye (this sign is very important and may be due to a fracture of a part of the retina requiring immediate treatment)
• Seeing flashes, when not accompanied by any other eye problems, require no treatment, and eventually improve spontaneously.
Eye Floaters and Flashes Brochure