In Photoshop CS there is a new tool called the Color replacement tool. You can find it under the Healing brush or Patch tool.

This will allow you to sample areas of color to replace in areas such as the eye. This is a great tool for getting rid of red eye. This tool automatically uses blending modes to ensure that the texture and density of the underlying area remains so that you’re not just ‘painting’ a color with a regular brush.
 

Remember to make a copy of your layer by dragging it to the new layer icon so you can go ahead and change pixels on it.

You can use it to brighten up the iris part of the eyes a little like this after sampling the skin.

Here I’m sampling some of the white of the eye to see if it will help replace some of the red eye. This is another use for the color replacement tool.

Since the eyes could use some more whitening, go ahead and make a selection with the magic wand tool on add to selection of the whites of the eyes.

You can add a small feather to it if you want so the edges are a little softer to fade the adjustment.

Now create a custom adjustment layer by going to the Levels adjustment layer option from the pop up menu on the bottom of the layers palette. Now just carefully whiten the eyes by dragging the white slider towards the left. This will brighten only the selected area. Because we made a selection first you are only applying the adjustment to the selection which is what’s visible.

The rest of the adjustment layer is masked automatically because you made the selection first so only the eyes are whitened (because you selected them). Making a selection of an area with this method is what I call a custom adjustment layer.

If the effect is too strong (remember not to blow it out of proportion), we still want it to look realistic and to see some of the veins faintly, then you can lower the opacity of the adjustment layer.

Now we’re going to do another industry technique. Press Alt and then click on the new layer icon to get the new layer dialog box.

Choose Gray as the color.

Choose overlay blending mode for now and click on Fill with 50% Gray.

What you have just done is created a dodge and burn layer. You will see what we do with it shortly.

Now grab a nice soft, medium sized brush (B).

Note that this layer is filled with 50% gray in the layers palette. This dodge and burn layer will allow you to accentuate either highlights or shadows in the image.

Make sure that your brush (not the layer) has a low opacity such as 3-5% if you’re making small adjustments or much higher for experimentation.  Go ahead and try it...Grab your soft brush tool and use white as your foreground color. This will allow you to ‘dodge’ or ‘add light to’ an area. It’s a photographer’s darkroom term where they extract an area so it doesn’t ‘burn’ as dark as the other areas when developing. Anyways, you use it to lighten or bring out highlights. You could use dodge and burn tools on the 50% gray layer as long as you have a low opacity.

Try dodging around the eyes to lighten them. You can have airbrush turned on if you want...this allows the residual brushholding to soak in and strengthen the effect.

This is a great technique for highlighting and bringing out extra life in the eyes.

Now switch to black as your foreground color and start ‘burning’ (letting more light saturate in) to areas which are already a little darker. This will help accentuate them such as this area here underneath the eyelid.

When you hide the other layers in the layers palette you’ll probably see something like this.

Once again it is the blend mode that is doing the magic here so you don’t see the actual black grey and white colors when other layers are visible because it is the blending mode that is automatically mixing the density and luminosity (depending on your blend mode) with the light of the layers above and below.

The blend modes you’ll use most often for this are Soft Light and Overlay on the actual dodge’nburn layer itself. This allows the light to magical appearance of accentuating shadows or highlights with this technique.

Now try bringing the brushes opacity up to 100% so you can see more of an effect.

Here you can get some really rich, vibrant highlights or shadows. Most often you’ll not want to do this strong of an effect but it’s fun to play around with it so let’s do that for a bit.

See the eye I’ve gone ahead and dodged it (white as foreground color) and then burned (black as foreground color) the area around with the brush. You can easily create thick long rich lashes with Maybelline, I mean with a really small ‘burn’ brush on a strong opacity.

Here you can see the 50% gray layer has the strong extremes of black and white which will bring out the much more vivid overlay effect of the colors. You can always switch to soft light too which won’t be as vivid.

Here I’m just painting thicker lashes and also cover some of the face with the darker ‘burn’ brush. The lower your opacity (of the brush) the less strong of an effect of dodging or burning. Remember that you’ll want to use white as your foreground color to work on lighter areas to help highlight them and vice versa.

If you ever want to reset the layer, the easiest way is to go to Edit: Fill (of course with the layer being selected/highlighted in the layers palette) and then choose 50% gray to get it back to it’s original state (wiping out your work though).

Here with the burning method I’m painting some thick makeup around her eyes like we’ve all seen before in impractically high fashion magazines, runways or on Shirley Manson from Garbage.

I don’t know why but I felt like adding this face paint to her...have fun with it; but remember the underlying concepts I’ve covered (and cover a lot more in practical tutorials in the Photo Retouch DVD training); that you’ll use a lower brush opacity to accentuate unless you want to have fun like this.

Say that you fool around and get the eyes where you want them to be but not the rest.

Here’s a method that you won’t likely find anyone else teaching you: 

Copy the layer by dragging it to the new layer icon (to retain an original), hide the copy and then select the original layer and add a layer mask as shown.

Now you can go ahead and grab a large soft brush (use right ] key to get larger brush and [ for smaller), get black as your foreground color and now that you’re on the layer mask (auto after you create it) go ahead and mask away the rest of the pixels other than the area you want to keep such as the eyes. I cover layer masking in depth in my Basic Photoshop training but this is another practical way in which to use layer masks. It’s better than using the eraser because you can always come back to or reveal the pixels you masked or had hidden.

Voila, here’s where we’re at for now.
These techniques should take you much further but if you’re really serious then you’ll just have to get my Discover Photoshop: Retouching DVD where I also reveal the #1 secret of the highest end retouchers- and show you how to use it. 

You can also browse the Discover Photoshop catalog for Photo Retouching tutorials.