Darwin theorized that emotional expressions originated as opposing functional adaptations for the expresser, not as distinct categories of social signals. Given that two thirds of the eye's refractive power comes from the cornea, we examined whether opposing expressive behaviors that widen the eyes (e.g., fear) or narrow the eyes (e.g., disgust) may have served as an optical trade-off, enhancin...

Non-invasive wavefront sensing of the human eye provides the necessary information to design corrections which minimize the monochromatic optical errors of the eye beyond simple sphere (defocus) and cylinder (astigmatism). These "ideal" corrections must move with the eye, maintaining proper alignment with the eye's optics. Viable modes of correction include contact lenses, refractive surgery an...

PURPOSE To compare the long-term results (9 years) of LASIK in one eye and phakic intraocular lens (implantable contact lens [ICL]) implantation in the fellow eye of the same patient. METHODS A patient with high myopia underwent LASIK with a MEL 60 excimer laser in one eye (spherical equivalent refraction -9.75 diopters [D], 5-mm optical zone with no transition zone) and phakic intraocular le...

Fixational eye movements remain a major cause of artifacts in optical coherence tomography (OCT) images despite the increases in acquisition speeds. One approach to eliminate the eye motion is to stabilize the ophthalmic imaging system in real-time. This paper describes and quantifies the performance of a tracking OCT system, which combines a phase-stabilized optical frequency domain imaging (O...

PURPOSE To investigate the short-term influence of imposed monocular defocus on human optical axial length (the distance from anterior cornea to retinal pigment epithelium) and ocular biometrics. METHODS Twenty-eight young adult subjects (14 myopes, 14 emmetropes) had eye biometrics measured before and 30 and 60 minutes after exposure to monocular (right eye) defocus. Four different monocular...