The invention relates to a device comprising one left electrochromic filter (3) and one right electrochromic filter (4) controlled by an electronic device (12). Said electronic device has means for controlling at least one filtering parameter, said means being actuatable by the user and programmed by a professional ophthalmologist, or a combination of the two. The aim of the invention is to provide variable filtering for the vision of a user of the device.
1. DEVICE FOR ASSISTING AND PROTECTING VISION, comprising one left electrochromic filter (3) and one right electrochromic filter (4) governed by an electronic device (12); characterized in that it presents control means of at least one filtering parameter, actuatable by the user, programmable by a professional ophthalmologist or a combination of the two; with the object of establishing a variable filtering of the spectral transmittance in the vision of a user of the device. 2. DEVICE FOR ASSISTING AND PROTECTING VISION, according to claim 1, characterized in that the variable filtering is established for the absorption of the short wave lengths in at least the 400 to 550 nm band. 3. DEVICE FOR ASSISTING AND PROTECTING VISION, according to claim 1 or 2, characterized in that said assisting device is achieved optionally combined with an standard optical correction element such as some prescription glasses. 4. DEVICE FOR ASSISTING AND PROTECTING VISION. according to claim 3. characterized in that the assisting device consists of a series of supplements that are coupled to these prescription glasses. 5. DEVICE FOR ASSISTING AND PROTECTING VISION, according to claim 4, characterized in that the electronic device (12) is included in one of the sidepieces (2) of a glasses body (1) wherein the areas of the frame that are in front of the eyes of the user include the referred electrochromic filters (3, 4). 6. DEVICE FOR ASSISTING AND PROTECTING VISION, according to any one of the previous claims, characterized in that the electronic device (12) presents supply means and has a D/A converter (6) the output of which is connected to the electrochromic filters (3, 4), while to its input a memory (5) and a control circuit (7) are connected which through an A/D converter (9) connects with an external potentiometer (8) and through a connection module (10) is coupled to an external connector or terminal (11); such that this terminal (11) forms the referred programmable means and the potentiometer (8) forms the above-mentioned means actuatable by the user. 7. DEVICE FOR ASSISTING AND PROTECTING VISION, according to claim 6, characterized in that said memory (5) is an EPROM memory, the control circuit (7) is a PIC circuit or a general purpose microcontroller, the connection module (10) is RS-232-type and the external terminal (11) is USB-type. 8. DEVICE FOR ASSISTING AND PROTECTING VISION, according to claim 6, characterized in that the supply means consist of a rechargeable battery located in a belt of the user and cable-connected to the rest of the electronic device (12), or else on a button cell located in the frame of the corresponding glasses (1), 9. DEVICE FOR ASSISTING AND PROTECTING VISION, according to claim 6, characterized in that the external potentiometer (8) consists of a variable resistor of sliding or rotating control, or else of two buttons with associated electronic circuitry respectively facilitating an increase and decrease of the filtering carried out by the electrochromic filters (3. 4). 10. DEVICE FOR ASSISTING AND PROTECTING VISION, according to claim 6, characterized in that said external terminal (11) forming the programmable means is capable of being complemented or substituted by infrared or radiofrequency wireless programming means applicable to the control circuit (7). 11. DEVICE FOR ASSISTING AND PROTECTING VISION, according to any one of the previous claims, characterized in that it has feedback means applied to the electronic device (12) and determined by photodiodes located in front and behind the electrochromic filters (3, 4). 12. DEVICE FOR ASSISTING AND PROTECTING VISION, according to claim 11, characterized in that it has a programming distinguishing the type of environmental illumination using the signs of the referred photodiodes, consequently acting on the electrochromic filters (3, 4). 13. DEVICE FOR ASSISTING AND PROTECTING VISION, according to any one of the previous claims, characterized in that it has some voltage wave forms exciting the electrochromic filters (3, 4) specifically adapted to its operation, continuous or alternate, these being square with variable work cycle or triangular or sinusoidal, with the object of optimizing the current draw of said filters (3, 4). 14. DEVICE FOR ASSISTING AND PROTECTING VISION, according to any one of the previous claims, characterized in that the referred control means are capable of being achieved in such a way that they independently act on the left electrochromic filter (3) and on the right electrochromic filter (4), or else in such a way that they act jointly on both of them (3, 4).