Drawing eye reflections requires an awareness of your light source and the spherical shape of eyeball. Eyes only display reflections because they mirror the source of light that enables you to see them. Sun and electrical light affect eye reflections differently. Sunlight tends to diffuse highlights around the eye. Electrical lights result in a concentrated reflection that bears the distinct shape of the light source. The curved surface of the eyeball distorts shapes in reflections. For instance, a rectangular camera flash or window appears as an elongated, curving shape on the eye.
Examine the eye that you wish to represent. If drawing from a live model in natural light, look for reflections from windows. If located outdoors, remain aware of the soft reflections around the iris. Finally, if you work from a photograph, study the eye for reflections from a camera lens. Often, these bright flashes create strong highlights around the pupil or distorted rhomboid shapes just beneath the top eyelid.
Draw small shapes inside of the eye that capture those you observed in your subject. Make these shapes light, since you will later blend their edges into surrounding shades or colours.
Colour or shade around your lines according to the appearance of your subject. Make the colours and shadows around your shapes dark and intense when appropriate to your subject to enhance the brightness of your highlights.
Blend the lines of your shapes, making sure that you leave no hard lines to define your reflections. Refraining from covering your original pencil lines may result in an unnatural appearance.
Take note of highlights and reflections caused by the shape of the eye. Since the eye is spherical, it tends to catch light just under the top lash line and above the bottom lid as it rounds out of the eye socket.