The fact that you had RK in past suggests that your eyes were myopic. Myopic eyes are comparatively large esp. length wise to normal eyes. We are all born with gel like substance called vitreous filling inside eyes giving them shape and form. This vitreous volume remains constant but due to myopia eye in enlarging and vitreous can t keep up with it, hence leads to development of degeneration( gel becomes liquid) of vitreous. Few of normal or abnormal tissue float in this liquid , seen as floaters by patient. As you mentioned your also seeing bright and black spots, this could be tear in retina which is commonly preceded by vitreous degeneration. These tear eventually lead to Retinal detachment(sudden loss of vision). But the good news is, if tear is detected earlier this can be prevented. You need to visit Ophthalmologist regularly for evaluation of development of any tear and treatment accordingly. Regards.