Abstract: A universal vision corrector particularly applicable to myopia, hypermetropia,astigmatism and presbyopia comprises, in front of the eye, an opaque zone (2) surrounding a small central area (3) situated in the vision axis, said small central transparent area (3) forming diaphragm and creating a reduced retinal giving a net vision. The opaque zone (2) is continuous, has a minimum average diameter of 3 mm and a maximum average diameter of 8 mm to preserve the peripheral vision and the central transparent area (3) has the surface comprised between 0.2 and 3.5 mm.sup.2, and preferably between 0.5 and 1 mm.sup.2.

Abstract: Method for obtaining clear plant juices and for the recovery of valorizable constituents wherein the juice from the pressing is subjected to a plurality of ultrafiltration stages, of which at least one is effected on a membrane with a molecular cutoff point on the order of 15,000 to 25,000. The temperature of introduction of raw juices is adjusted to T.degree. C.=-6 PH +80.degree. C..+-.3.degree. C. Clear juices and valorizable constituents are obtained by this process. Application to the production of fruit and vegetable juices with preservation of the pigmentation is also disclosed.