Vision lowering is about.

As worsening vision in eyes diseases or functional disorders.Reasons are many, as organic and functions, as organism are eyes diseases in ophtalmologic tests are myopia, glaucoma, cataract,hypermetropia, but a few diseases are not found,that lead to bad vision, this is as functional lowering vision in astenopia.Astenopia is fast eyes tired in vision work, in small distance from eyes till object, in a high muscles eyes loading,fatigue, as provokers are whole diseases and intoxication's, as after 40 y.old she is rising because of aging eyes forces changing.

Symptoms are poor  lines closed  of detailed viewing, hard defining words, items, tired eyes, heaviness, headache,eyes in aches after long work on the near distance, dioplia in vision work on near distance, which is faster removing, if to close one eye, glasses are not improving vision, on tests are not observing changes for eye hole and refractions.

As at the doctor you are getting tests are on vision sharpness, eyes hole, tonometria, perimetria.

Cure are right,same light on the vision work and on near distance, rest for eyes is often, sleep good, whole strengthening, eyes drops, vitamins A.
As eating meal with such vitamin are liver beef, lard, cod, eggs, caviar cetaceas are vision improves, so as he is forming in organism of beta carotene, as using complexes of, and meal are hippophae, carrot red, red pepper, onion green, spinach, sorrel, blueberry, are of vitamin C, as improving all eyes structures.
As good supporting vision for are exercises for muscles eyes training,are regular doings and effectively and improving vision.

Vitamins A, beta carotene are vitrum, multi tabs maxi, retinol acetat, trivi plus, vitrum vision, strix, blueberry fried extractum.
Eyes drops are in a high vision loads are digofton, emoxipin acos.