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Pseudomonas aeruginosa can cause ocular surface infections such as keratitis, a sight-threatening inflammation of the cornea, particularly in contact lens wearers. To effectively model ocular surface infections, is important to first understand interactions between components of the ocular surface environment such as the cornea, tear film, commensal microbiota, invading pathogens, and factors such as contact lens wear. Investigations presented in this doctoral thesis represent a series of related but distinct studies designed to contribute to the further understanding of these interactions, with the ultimate aim of developing a representative in vitro model of the cornea and ocular surface for infection studies. To characterise the microbiome of contact lens wearers and non-contact lens wearers, tear fluid was collected using a microcapillary technique and analysed by 16S ribosomal RNA (rRNA) sequencing. Genera such as Staphylococcus, Corynebacterium and Propionibacterium were found to have the highest relative abundance across samples. Pseudomonas had higher relative abundance in contact lens wearers, with a specific operational taxonomic unit (OTU) found to be significantly higher relative abundance following DESeq2 analysis. Following the characterisation of the microbiome, the effects of antimicrobial tear proteins, such as lysozyme and lactoferrin, on the growth and virulence phenotype of novel clinical isolates of P. aeruginosa were investigated. The addition of proteins to cultures in complex media significantly decreased carrying capacity (P < 0.0001). Growth in a complex salt medium that was compositionally similar to tears was associated with a significant decrease in the carrying capacity and growth rate of the culture and a significant increase in generation time. This is likely due to nutrient limitation, suggesting a further feature of the tear film in conferring protection against infection, in addition to direct antimicrobial functions. When investigating the effect of tear proteins on virulence phenotypes, protease and pyocyanin production were unaffected following exposure of isolates to lysozyme and lactoferrin, with haemolytic activity significantly increased in all but one test bacteria (P < 0.0001). Swimming motility was significantly increased in three organisms (P < 0.05) and swarming motility was significantly decreased in one (P < 0.05). This suggests that these particular tear innate immune factors have various effects on virulence phenotype which may be due to the upregulation of virulence factor production by the associated quorum sensing signalling pathways. Experiments to assess the effect of contact lens materials on biofilm formation indicated that silicone hydrogel materials such as senofilcon A and comfilcon A support biofilm growth more favourably than hydrogel materials such as etafilcon A and omafilcon A. This is important since silicone hydrogels are used in extended lens wear, with users at higher risk of P. aeruginosa keratitis. To understand the interaction between lenses and the tear film, lenses were soaked in lysozyme solution before inoculation with the test bacteria. A significant reduction in P. aeruginosa attachment to etafilcon A (P < 0.05-0.01) was observed, suggesting this hydrogel material adsorbs lysozyme more readily. To build on these findings, the final aim of this doctoral study worked towards developing an in vitro model of the ocular surface that could be translated to infection research. Primary human stromal cells and corneal epithelial cells were successfully cultured from donor corneas and incorporated into and onto the surface of a collagen gel. Culturing epithelial cells in a high Ca2+ medium was found to provide the most integral epithelial multilayer. The addition of stromal cells and a fibronectin basal lamina substitute to the collagen gel were found to further improve epithelial growth. To conclude, this model could be further developed for use in studying ocular surface infections by incorporating an antimicrobial tear film and other ocular surface components and could be used in conjunction with bacteria and contact lenses to further understand the complex interactions investigated in this thesis.