problems with screen/ videocard

Since one day i got a problem with my macbook pro. Screen doesn't work anymore. When i try to do a hard reset, i get it back from time to time. I got this panic report from apple when i get started again. Does anyone know what it means?

*** Panic Report ***

panic(cpu 6 caller 0xffffff7fa3251a0f): "GPU Panic: mux-regs 2 0 a0 99 0 8 severity 3 WS-ready 1 switch-state 0 IG FBs 1 EG FBs 0:0 power-state 6 3D idle HDA idle : NVRM[0/1:0:0]: Read Error 0x00137310: CFG 0xffffffff 0xffffffff 0xffffffff, BAR0 0xc0000000 0xffffff91476ec000 0x0e7150a2, D3, P0/4\n"@/BuildRoot/Library/Caches/com.apple.xbs/Sources/AppleGraphicsControl/Ap pleGraphicsControl-3.18.52/src/AppleMuxControl/kext/GPUPanic.cpp:162

Backtrace (CPU 6), Frame : Return Address

0xffffff812d78b1d0 : 0xffffff8021a6d166

0xffffff812d78b220 : 0xffffff8021b95824

0xffffff812d78b260 : 0xffffff8021b87b10

0xffffff812d78b2e0 : 0xffffff8021a1f180

0xffffff812d78b300 : 0xffffff8021a6cbdc

0xffffff812d78b430 : 0xffffff8021a6c99c

0xffffff812d78b490 : 0xffffff7fa3251a0f

0xffffff812d78b4f0 : 0xffffff7fa26e1e45

0xffffff812d78b570 : 0xffffff7fa27afd59

0xffffff812d78b5d0 : 0xffffff7fa48ba230

0xffffff812d78b600 : 0xffffff7fa2717c60

0xffffff812d78b780 : 0xffffff7fa494bfed

0xffffff812d78b810 : 0xffffff7fa494be14

0xffffff812d78b830 : 0xffffff7fa26e2d42

0xffffff812d78b8b0 : 0xffffff7fa26e5dce

0xffffff812d78ba30 : 0xffffff7fa26e7bad

0xffffff812d78bb30 : 0xffffff7fa28bd0c9

0xffffff812d78bc30 : 0xffffff7fa2677583

0xffffff812d78bcc0 : 0xffffff7fa265bfff

0xffffff812d78bd30 : 0xffffff7fa265ecfc

0xffffff812d78bd90 : 0xffffff7fa265e873

0xffffff812d78be00 : 0xffffff7fa260e994

0xffffff812d78be50 : 0xffffff7fa260e6fc

0xffffff812d78be80 : 0xffffff7fa26150d3

0xffffff812d78bed0 : 0xffffff80220997f5

0xffffff812d78bf30 : 0xffffff8022097f62

0xffffff812d78bf70 : 0xffffff802209759c

0xffffff812d78bfa0 : 0xffffff8021a1e4f7

Kernel Extensions in backtrace:

com.apple.iokit.IOGraphicsFamily(519.19)[0B3857C5-9040-3A0C-BFB4-C45E56DB01C6]@ 0xffffff7fa2604000->0xffffff7fa264cfff

dependency: com.apple.iokit.IOPCIFamily(2.9)[1057F053-73DE-33E4-B5BE-09DA28715DB4]@0xffffff 7fa2294000

com.apple.iokit.IONDRVSupport(519.19)[3B9AF334-51BC-3DCC-95B2-DC7386BB16FF]@0xf fffff7fa265a000->0xffffff7fa2669fff

dependency: com.apple.iokit.IOGraphicsFamily(519.19)[0B3857C5-9040-3A0C-BFB4-C45E56DB01C6]@ 0xffffff7fa2604000

dependency: com.apple.iokit.IOPCIFamily(2.9)[1057F053-73DE-33E4-B5BE-09DA28715DB4]@0xffffff 7fa2294000

com.apple.driver.AppleMuxControl(3.18.52)[971DAA01-FE8B-39AD-BCFE-9BB81DCA55CD] @0xffffff7fa3243000->0xffffff7fa3255fff

dependency: com.apple.driver.AppleGraphicsControl(3.18.52)[6A280175-7E90-3F8B-BFE2-3C181C22 2BD9]@0xffffff7fa3213000

dependency: com.apple.iokit.IOACPIFamily(1.4)[95DA39BB-7C39-3742-A2E5-86C555E21D67]@0xfffff f7fa2d86000

dependency: com.apple.iokit.IOPCIFamily(2.9)[1057F053-73DE-33E4-B5BE-09DA28715DB4]@0xffffff 7fa2294000

dependency: com.apple.iokit.IOGraphicsFamily(519.19)[0B3857C5-9040-3A0C-BFB4-C45E56DB01C6]@ 0xffffff7fa2604000

dependency: com.apple.AppleGraphicsDeviceControl(3.18.52)[FC5E4CD4-7730-3A55-9CC5-338A64F50 E42]@0xffffff7fa266a000

com.apple.nvidia.driver.NVDAResman(10.3)[8FD3D7CE-1199-359A-AB76-7298BBE22C8D]@ 0xffffff7fa2675000->0xffffff7fa294efff

dependency: com.apple.iokit.IOPCIFamily(2.9)[1057F053-73DE-33E4-B5BE-09DA28715DB4]@0xffffff 7fa2294000

dependency: com.apple.iokit.IONDRVSupport(519.19)[3B9AF334-51BC-3DCC-95B2-DC7386BB16FF]@0xf fffff7fa265a000

dependency: com.apple.iokit.IOGraphicsFamily(519.19)[0B3857C5-9040-3A0C-BFB4-C45E56DB01C6]@ 0xffffff7fa2604000

dependency: com.apple.AppleGraphicsDeviceControl(3.18.52)[FC5E4CD4-7730-3A55-9CC5-338A64F50 E42]@0xffffff7fa266a000

com.apple.nvidia.driver.NVDAGK100Hal(10.3)[C22CA1DB-66EE-39BE-878F-7E6110C7C99B ]@0xffffff7fa4880000->0xffffff7fa4a2dfff

dependency: com.apple.nvidia.driver.NVDAResman(10.3.0)[8FD3D7CE-1199-359A-AB76-7298BBE22C8D ]@0xffffff7fa2675000

dependency: com.apple.iokit.IOPCIFamily(2.9)[1057F053-73DE-33E4-B5BE-09DA28715DB4]@0xffffff 7fa2294000