How to Paint The Human Eye
Professional illustrator Cat Reyto offers the tutorial below on how to paint the human eye using Photoshop. For more insights from Cat, visit her website. Take it away Cat.
I’ve had the pleasure of teaching this lesson in several different courses: Digital Painting in Photoshop, Digital Illustration in Illustrator, and Traditional Illustration, with regular ol’ pencil and paper. That variety has provided me with the opportunity to mix all my favourite tips and techniques together, forming one big scrapbook of a tutorial.
The fundamental aspect of this lesson remains consistent in all three methods: the importance of values. Painting the eye is largely a study in how light falls on different shapes. If you keep that in mind as you paint, you’ll find eyes to be much more of a pleasure than a challenge to achieve a heightened sense of realism.
For this tutorial, I’ve used my own right eye as a reference, by placing a mirror on my desk. I’ve found it to be a method of study far superior to a photo reference, and highly recommend it as you follow these steps.
First, a little lesson in lighting…
To give you a rough idea about how light falls on the eye, imagine a car parked in a garage, with the garage door ¾ open and the front of the car poking out just slightly. Imagine the sunlight hitting the front of the hood, just above the bumper, so that it reflects brightly in the sheen of the paint. Now compare that idea to the eyeball, and the eyelids surrounding it.
Now, let’s imagine how the garage interacts with the sunlight. Since there is no light reaching the rear of the garage, it’s in deep shadow. The car itself is blocking light from hitting the ground directly below it, so we find shadow under the hood as well. And lastly, the ¾ door casts a long shadow over the windshield of the car.
The garage door, like the upper lid, blocks light from falling over the top of the windshield (upper eye). The ground underneath the car casts a light shadow around the lower body of the car (lower eye).
The rear of the garage, deep in shadow, is similar to the corners of the eye where the lid creases meet one another. And finally, the hot light reflecting off the paint on the hood of the car is like that spot of reflected light that tends to hover just over the pupil.
The car-garage concept should serve as a good visual comparison to how light falls on the sphere shape of the eye, while being blocked by the angle and slant of the lids.
The most important rule of thumb in drawing the eye is to avoid drawing opaque lines. For example, the line that forms the crease of the upper eyelid is in fact a very deep fold. When you paint in the shading with low-opacity, saturated colours, the results are far more lifelike.
This diagram shows the main areas of shading that we’ll be dealing with. Note the direction of the hatched lines – they follow the curve of the eyeball.
- We begin with a blank canvas (white background). I chose w 6” x h 6” at 300 dpi. Even if you are planning on transferring to a full portrait, this is still a good starting point, as it will be easier to build skin around them than blend them into an already detailed face.
- Fill the canvas with a mid-tone skin colour. It needs to be not too pale or too dark, as all the shadows and highlights will need to blend into it.
- For your exact mid-tone colour choice, you must have a good idea of the who/what/where of your character. Ethnicity, age, state of health and light temperature (outdoor/indoor, summer winter) are all called into question. Bring the colour-picker circle upwards and over to the left, so that it’s still saturated with warm orange-brown, but in a lighter hue and tint.
- Test out a variety of mid-tone colours first to be sure you’re happy with it. Make sure it has a warm feeling.
- The palette: basic shadows and highlights. Create a new layer and name it “palette.” Here you’ll drop blobs of opaque values that you’ll sample with your brush as you add shading.
- To create the outline, I’ve begun with the spherical shape of the eyeball, on its own layer, which I will later delete. For now, it will serve as a great guide for shadow placement. Notice that I’ve left enough room around the eye area to account for the surrounding skin. This all counts as part of the eye, meaning the bone and muscle tissue that hold it in place.
I’ve used the Ellipse tool to create a circle, holding shift + alt (opt) as I drag it out, to maintain its proportions. Notice how the rims of both eyelids are visible, as well at the tear-ducts and eyelids. My palette is placed close by, on a separate layer.
- Using the default Hard Round Brush with Pressure Opacity on, I’ll begin painting in the basic areas of shadow and highlight. The most important step is to paint on low opacity; I began at 10% and never moved up beyond 20%. Hold your pen lightly on the tablet’s surface, as the lightness of your strokes will make all the difference for achieving good blending, as well as a soft, painterly look.
Notice that I’ve added some new colours to my palette: a Greyish purple, a deep orange-brown, an orange-beige, and a yellow-beige. Once I’ve used my original hues to lay down the basic shadows and highlights, I can begin to further define them and add richness with these warm, saturated colours.
You’ll be able to highlight and shade using these colours alone.
Note: People often find it challenging to get accustomed to using the purple hue. But blending it lightly with orange creates a depth that does well to mimic the tone of the blood vessels under the thin layer of skin surrounding the eye.
I routinely use the Eyedropper tool (it’s set up on the lower button of my Stylus) to select my background colour. I’ll use it to blend as I paint light, overlapping strokes.
The direction of the brush strokes is important for emphasizing the roundness of the eyeball and the contours of the skin. The directions are marked by the blue arrows.
- I continue to refine the shadows, now being a little bolder with the saturated colours. To emphasize the crease, I’ve run some long, light strokes of the purple and dark orange where the fold line is, then followed just above with similar strokes of the yellow-beige highlight colour. The contrast of light to dark is more pronounced with this use of complimentary colours: the yellow should jump forward, the purple will recede back.
- For the colour of the eye itself, it’s best to go with a greyish, very light beige, as opposed to pure white. Depending on the lighting in your scene, you may need to tone this down later, but it serves a good starting point. Once I’ve filled the eyeball area, I painted the background, mid-tone skin colour back inwards from the tear-ducts. This will make a natural transition. I’ve also lightly covered the greyish-white area with a thin layer of the mid-tone skin colour (at 10% opacity) for the same reason.
- The iris is the most compelling part of the whole eye-painting experience. There are few solid rules to keep in mind, and the rest is really open to individual style.
On the layer where I drew the sphere shape of the eyeball, I’ll draw a verticle then horizontal line crossing through the centre of the circle. Ideally, this is where the centre-point of the pupil will end up.
On a new layer, I’ll draw an Ellipse from those crosshairs (holding shift + alt/opt), and dragging it out so that the upper lid covers the top of it, and the lower lid covers some, or at least the rim, of the bottom of the circle.
Note: This last point all depends on the angle expression of the face. Try out a few expressions and tilts of your head in a mirror to see for yourself.
Selecting a deep green (I’m using my own eye colour, but go with whatever you like, so long as it’s dark), I’ll run an outline around the ellipse, so that I’ve framed the perfect circle of the iris.
Note: The ‘perfect circle’ is my own preference. You may prefer to wing the circle shape, and I often do. You can get pretty close by free-handing it.
- To make things easier while colouring, I’m going to isolate the iris so I don’t paint all over the place. I’ll enter into Quickmask mode (q), and use 100% black (it will appear red in quickmask mode) to shave down the ellipse to the inside of the lids.
- Once my selection of the iris is complete, I exit Quickmask mode. To keep working on the selection without the noise of the dotted line distracting me, I’ll create a layer mask (see image). This way I can draw on the mask instead of the selection, which means I’ll be able to edit it later, while retaining the selection, if I’m so inclined.
- Now I can fill in the base of the iris colour. I’ll use a dark green, then go over it again with a slightly lighter shade of green, to give it a sense of depth. I like to leave a little of the darker colour around the perimeter of the iris at this stage.
- On a new layer, I’ll repeat similar masking steps to create the pupil. Remember that no matter where the eye is looking, the pupil always remains in the exact centre of the iris. Also, the size of the pupil depends on your light source. The more light the eye is exposed to, the smaller the pupil size, and vice versa (just like the aperture of a camera).
I’ll create a layer mask for the pupil. I’ll then create another layer for the reflected light, and a layer mask for it as well.
All these layer masks will come in handy while painting in the details. They may make things seem complicated if you’re not used to using them, but you’ll find they really simplify the creative process.
- I move away from the iris now to work on the overall shading once more. This stage can and probably should take a while, so take your time and observe your reference (if you have one) carefully as you paint.
I’ve added three new colours to the palette: a very saturated orange, a deep orange/red, and a greyish green. The new orange is used to elongate shadows and adds a lifelike warmth to the skin. The deep orange/red will be used mostly to emphasize creases, but will serve well for defining the rim of the eyelid around the eyeball. Its colour mimics the thin skin tissue, where capillaries are very close to the surface (and appear reddish). I’ll also use this colour to faintly paint in the shadow cast bye the upper lid (and soon to appear eyelashes) over the eye. I’ll use it as well to paint arc-like strokes in from the tear-ducts, establishing a smooth transition from the meaty tissue of the ducts to the eye.
The greyish-green isn’t used much, but is useful in adding shadow in the eye, as well as to compliment the deep orange-red in the crease lines (green opposite red on the colour wheel).
This stage is all about ‘sculpting’ the eye out from the canvas. Highlight/warmer colours are used to pull the shapes forward, whereas shadow/cooler colours should give it a sense of depth.
For additional emphasis, I’ve sometimes switched the colour mode to Multiply when using the deep orange/red. I’ve mostly kept the opacity low, ie. 10-20 %, but since I have so much paint built up by now, I can afford to jump up to 50% for added emphasis. My brush size varies constantly, depending on the level of detail.
- Painting in the iris detail is possibly the most satisfying part of the painting the eye; it’s here where the realism and personality meet and shine through. Before you begin, do an image search of eyes, and have a look at how the lines appear in varying ways with every colour and light source.
My own eyes are a hazel-green, so I’ve used some light brown around the inner rim (just outside the pupil), then varying shades of green, from dark to pale green-yellow, as the latter will mesh well with the brown. I’ve used the soft round brush for the most part, but to blend, I used a few of the texture brushes available in Photoshop’s default brush set.
I pooled most of the reflected light (paler greens) around the lower half of the circle, painting light strokes from the pupil to the outer rim of the iris. To achieve more depth, I switched to Multiply mode, especially to emphasize the deeper hue around the outer rim, and to cast a long shadow over the top. I used Screen mode, using the paler greens, to get a sense of glowing reflection. To blend and break up the lines somewhat, I used the smudge tool, with a speckled brush.
For the most part, I kept the reflection-circle layer hidden, but I toggled it on and off, as it gives a better idea of the end product.
- You can easily get away with great realism by just leaving the reflection dots as they are (maybe blend their edges a bit). But for a heightened realism, I like to carve right into these dots of light, conveying the impression of reflected objects (in my case, a window). I’ve found it works best if you just make the impression of an object but keep things abstract. I switched back and forth between the soft round brush (white, opacity 50%) and the eraser tool, with a hard round brush (also 50% opacity). Mix up hard lines with soft blurs to that sense of a liquid surface.
On a new layer, I used a very light blue to add in some extra hard reflections, as well as to lighten up the area of the eyeball where light is hitting. I used a cool grey to dull out the shaded area of the eyes (towards the tear-ducts).
- For the pupil, I added a Gaussian blur filter, which unites it better to the iris.
- I merged the eye, iris and pupil layers together, leaving the reflection layers separate. This way I can really get into the deep shadows: with a deep green set to multiply, I paint in the upper iris where it’s shaded by the upper lid (think of the windshield of the car in being shaded by the garage door). I also used deep green to paint lightly around the perimeter of the iris, blending it in with the white of the eye.
- Painting the eyelashes is a patient and delicate process. There are a few things to keep in mind before getting started. First, lashes don’t curve as much as you may think, but rather point out straight and down, then arch slightly as they taper off.
It’s important that you take into account that the density and length of the lashes will vary greatly from one subject to the next, so study those of your reference carefully. It’s extremely helpful to have a good look at your own lashes in a mirror first (without makeup), and study how the perspective changes their look when you turn your head slightly back and forth. Finally, it’s a good idea to take into account that in your final portrait, the eyes will be smaller than in your current canvas. So unless you want the lashes to stick out like sharp little daggers, it’s a good idea to keep them soft and light, and to constantly zoom out to compare views as you work.
Create a new layer for the upper lashes, and another layer for the lower lashes. I used a dark brown, toggling Multiply mode on and off as I added strokes, to achieve depth. I used a soft round brush with the size pressure on, and toggled opacity off to build density, and off to taper out the tips. The most challenging area for me is always in the centre of the upper lid, above the iris. This is because the lashes are foreshortened, that is, pointing straight, and only curving up slightly at the tips. From a straight angle (as we are working on here), it means creating the impression of the lashes, without seeming like they have been forced upwards with an eyelash curler.
I use the eraser tool to taper the tips of the lashes, so they look fine and slight as they taper out. Finally, I use the smudge tool to soften the look of them down considerably.
Once I’ve completed a semi-finished look, I’ll duplicate that layer, then shift this duplicate set over slightly. I’ll go in with the eraser once more, breaking up this second layer so that groups of lashes are a bit separated from one another. And once again, I smooth out with the smudge tool. Try playing with the opacity as well, as you may not need both layers at 100%.
The lower lashes are considerably more thinned out, not to mention shorter in length. I tend to just do a soft run of strokes across the outer rim of the lower lid, then go back again the opposite way. Then I’ll add some value to the areas where the lashes overlap. I’ll use the eraser and smudge tool once more.
For a finishing touch, I’ll use a lighter brown and create the impression of soft light (reflection off the eye) midway along the lash length, but only here and there. Too much will give them an unnatural appearance.
- The brow and final steps: The brow involves a bit of a teeter-totter technique: it’s a push-and-pull between definition and volume, and blending for an overall shape. The most important thing to remember is to follow the path of the brow-bone structure (the base of the forehead). Try feeling it for yourself, by placing the tips of your index and middle finger in the inner corner of your eye, then gliding them over and around the arch of your brow.
Mistakes often made:
a) Seeing the individual hairs. Clump them together in the thicker areas, and paint in skin tones in the more sparse areas. Use a soft round brush on low opacity (deep brown), to paint in “shadows” underneath. Use the smudge tool here and there
b) Making it look too neat. Eyebrow hairs tend to grow in from all over the place, so unless you’re working on a purposely manicured image, try adding in strays.
c) Hairs flowing in one direction. The hairs move with the shape of the brow-line, giving the overall shape a bit of an S-curve as they rise over the arch.
- Finishing off.
a) Adding texture: On a new layer, use a speckled brush (with opacity jitter on), and a yellow-white to paint in light dots of texture. You’ll want to do this with varying brush sizes, ie. A large brush for the brow area, and a very narrow one along the upper eyelid.
Take a look at your own eye for a moment, to observe the variations in skin types. It tends to be thin and oily around the inner-tear duct, and a bit thicker and smoother along the outer edge of the upper lid. Follow these patterns accordingly as you paint in texture.
Put this layer on Overlay, then duplicate the layer, and move the new one over slightly. With a speckled brush, go in with the eraser to take out and tone down certain areas of texture. Try experimenting with the opacity of each layer as well.
Note: Some people have more porous skin than others. If that’s the case, you may want to try adding another layer beneath these, with the same technique, except with a darker colour set to multiply.
b) Final details: By this point, you’ll likely have a hard time putting the pen down. The areas to focus on:
- “tightening” up the rim of the lower-lid against the eye
- refining the eyelashes (tends to mean erasing to form groups).
- Adding colour to the skin surrounding the eye, to give it a stronger frame-work (try a soft, swooping highlight over the brow)
- Adding soft oranges, purples and deep reds to key shadow areas to push them further back, and adding yellow-white to bring highlights further out.
- Touching up and further accentuating the reflective surface of the eyeball (try an arched motion)
- Adding in a few speckles of texture to the eyeball surface.
- As you work, zoom out constantly to observe how the eye looks from a distance. And like most projects, the best revisions are often made after you’ve taken a break for a bit.