welcome to just answer
are you present online?
there can be various causes of the spot that you are seeing in your eye-
it can be a floater. These are normally seen in older age. When the vitreous (thick jelly like fluid) gets separated form the retina, then floaters in teh form of spot/thread/ring can be seen. This usually moves with the movement of the eye. A floater is harmless
other possibility is a mild bleed in the vitreous humor, which can be seen in diabetic patients, trauma or due to a minor trauma to a blood vessel while the vitreous is getting separated from the retina. A bleed needs to be evaluated for the cause and treated accordingly
in cases of posterior uveitis (inflammation of the posterior part of eye), there might be presence of such spots seen in field of vision
rare causes are scotoma (obliteration of central part of vision) due to a problem of the optic nerve caused by pressure on it
I would recommend you to consult an Ophthalmologist for a detailed evaluation to rule out the above possibilities and to be treated if needed