Macbook Pro Mid 2010 NVIDIA GeForce GT 330M random glitch showing when scrolling, writing or watching videos I have have a MacBook pro late 2010 (now 4 years old), I use it everyday and there's a graphical issue where letters in the browser become blurry and broken, some kind of weird glitch happens all the time.
Problem
Whenever I scroll on a page or write content in an input, using google chrome letters become like this (click on the picture so you understand what happens).

This is very disturbing when reading.
What I tried
Other browsers
They work a bit better
I have tried on Opera browser and on Safari and this doesn't happen (at least, did not happen as often as chrome). I used firefox for a while now, went better, but Playing videos on firefox does the glitch too. I switched to Firefox Developer Edition and can't tell when was the last time I experienced an issue (see end of question and answers, may help too).
Disabling plugins
Nope. I created a new chrome user (with no plugin installed), still does that flickering.
Reinstalling Chrome
Nope. Tried this multiple times, still the same.
Trying other versions of Chrome
Nope. Thought it worked fine, used it for 30 minutes, does the same again.

Additional informations
I am currently running Yosemite but it's been doing this for a long time.
Hardware Overview:

  Model Name:   MacBook Pro
  Model Identifier: MacBookPro6,1
  Processor Name:   Intel Core i7
  Processor Speed:  2.66 GHz
  Number of Processors: 1
  Total Number of Cores:    2
  L2 Cache (per Core):  256 KB
  L3 Cache: 4 MB
  Memory:   8 GB
  Processor Interconnect Speed: 4.8 GT/s
  Boot ROM Version: MBP61.0057.B0F
  SMC Version (system): 1.57f17
  Serial Number (system):   ***
  Hardware UUID:    ***
  Sudden Motion Sensor:
  State:    Enabled

Intel HD Graphics:

  Chipset Model:  Intel HD Graphics
  Type: GPU
  Bus:  Built-In
  VRAM (Total): 288 MB
  VRAM (Dynamic, Max):  10
  Vendor: Intel (0x8086)
  Device ID:  0x0046
  Revision ID:  0x0018
  gMux Version: 1.9.22

NVIDIA GeForce GT 330M:

  Chipset Model:  NVIDIA GeForce GT 330M
  Type: GPU
  Bus:  PCIe
  PCIe Lane Width:  x16
  VRAM (Total): 512 MB
  Vendor: NVIDIA (0x10de)
  Device ID:  0x0a29
  Revision ID:  0x00a2
  ROM Revision: 3560
  gMux Version: 1.9.22
  Displays:
Color LCD:
  Display Type: LCD
  Resolution: 1600 x 1000
  Pixel Depth:  32-Bit Color (ARGB8888)
  Main Display: Yes
  Mirror: Off
  Online: Yes
  Built-In: Yes

Things that seemed to help
These are taken from the answers below (thanks!), read them for details

I had some unusual cpu usage after upgrading to yosemite, I followed 6 Easy Tips to Speed Up OS X Yosemite on Your Mac (first one helped alot).

I disabled hardware acceleration in chrome about:config

I enabled subpixel font rendering for non-Apple LCDs:
   defaults write NSGlobalDomain AppleFontSmoothing -int 2
I have experienced the same glitch.

This seems to be the problem reported here: https://code.google.com/p/chromium/issues/detail?id=359108

They claim it's an issue with Mavericks, GPU-accelerated graphics, and the NVIDIA GeForce GT 330M. I also have a mid-2010 Macbook Pro with the same graphics chip

This glitch started happening on mine after I upgraded to Mavericks. Also my Macbook started rebooting spontaneously every couple of weeks, with kernel panic messages about the GPU.

The suggested workaround is to go into Chrome's advanced settings, and disable the checkbox for "Use hardware acceleration when available" (second from the bottom). Then restart Chrome.

I just tried that myself, so I can't report that it works reliably yet.