A formalism is developed to investigate the instability and the time of rupture of thin films which are subjected to finite amplitude perturbations. The hydrodynamic and the interaction force nonlinearities cannot be ignored in such an event. The key idea of the approach is that, for a finite amplitude perturbation, one needs to study the instability of the corresponding finite amplitude, spati...

Conjunctivochalasis (CCh) disrupts tear flow and damages tear film stability. This study sought to evaluate the tear stability and contrast sensitivity of patients with CCh on whom CCh excision was performed. The study included 39 eyes from 39 patients; all patients had eyes with grade 2 or 3 CCh, underwent CCh excision, and were evaluated before and three months after the surgery. The evaluate...

INTRODUCTION Dry Eye is a multifactorial disease of the tearfilm and the ocular surface which may be due to reduced tear production or excessive tear evaporation resulting in discomfort, visual disturbance, and tear film instability with a potential damage to the ocular surface. Various population-based studies have been done to find out the prevalence and the magnitude of the problem. Women He...

The authors previously found that measurements of precorneal tear film thickness in animals, using laser interferometry and confocal microscopy, were larger than earlier estimates. They proposed that this occurred because optical methods did not disturb film structure and measured full thickness, including mucus. In the present study, tear film thickness was measured in humans. Coherent light w...

PURPOSE To determine the repeatability of real-time optical coherence tomography (OCT) measurements of tear film thickness (TFT) and variables of tear film menisci. METHODS Forty eyes were imaged with a custom-built, real-time OCT to obtain heights, curvatures, and cross-sectional areas of upper and lower tear menisci simultaneously. The central TFT was indirectly determined as the difference...

PURPOSE Kinetic analysis of sequential tear interference images was used to investigate how the precorneal lipid film spread and distributed in aqueous tear deficiency (ATD) dry eye. METHODS One eye of 17 patients with ATD was randomly selected for this noncomparative case series. Twelve patients also had noninflamed meibomian gland dysfunction (MGD). Sequential images were digitized and anal...

Biophysical properties of the tear film lipid layer are studied at the molecular level employing coarse grain molecular dynamics (MD) simulations with a realistic model of the human tear film. In this model, polar lipids are chosen to reflect the current knowledge on the lipidome of the tear film whereas typical Meibomian-origin lipids are included in the thick non-polar lipids subphase. Simula...

The cornea is the anterior most surface of the eye and plays a critical role in vision. A thin fluid layer, the tear film, coats the outer surface of the cornea and serves to protect, nourish, and lubricate the cornea. At the same time, the tear film is responsible for creating a smooth continuous surface, where the majority of refraction takes place in the eye. A significant component of visio...

This thesis deals with an interesting application of mathematics, tear film dynamics. Our goal is to understand and simulate the various observed tear film behaviors, such as film cooling, black line formation and lipid patterns etc. During this process, we build models to describe the fluid dynamics for several blink cycles, experiment on the choices of parameters, compare the simulation with ...

A lateral shearing interferometer designed and built for the study of the precorneal tear film topography dynamics and its effect on visual performance is presented. Simple data processing algorithms are discussed and tested on data illustrating different tear topography features: postblink tear undulation, tear breakup, eyelid-produced bumps and ridges, bubbles, and rough precontact lens tear ...