You must get a fundus examination to ensure that everything is fine. Myopics are more more prone to retinal taers and retinal detachments. Your symptoms could be because of a posterior vitreous detachment which is a normal ageing change. The vitreous gel in the posterior part of the eye liquifies with age and shrinks. As it shrinks, it may cause traction on the retina which may lead to flashes of light(not necessary) and floaters in the eye. Usually, it goes uneventful, but sometimes it amy cause a retinal tear which can lead to retinal detachment and serious loss of vision. So, a person with these symptoms must get a dilated fundus examination to rule out any retinal tear. A refractive error may also be present. Other less likely possibilities inclue ocular migraine and age related macular degeneration. Thanks.
Please, click the ACCEPT BUTTON so that I can get my dues. BONUS and a POSITIVE FEEDBACK will be appreciated