The marketing of electronic cigarettes (e-cigarettes) in 2003 was initially intended to present a healthier alternative to smokers. Subsequently, it became an extremely widespread fashion phenomenon, especially among young people. It thus contributes to attracting new consumers thanks to its modern and technological presentation, combined with a panoply of captivating fragrances.

In 2014, the FDA still does not recognize this practice as a substitute for smoking intended to limit it, and several recent studies have demonstrated the potential harmful effects of e-cigarettes on health. Indeed, the latter also have pulmonary effects reminiscent of those of the original cigarette, namely breathing difficulties or even lung inflammation.

In addition, a potential impact on the vascular system has recently been highlighted by the use of these e-cigarettes. Thus, their components can lead to vascular changes in the reactivity of blood vessels, an increase in blood pressure or even endothelial dysfunction and vascular and cerebral oxidative stress.

The aim of this study is to detect these phenomena at the level of the retinal circulation, window of the central nervous system, in order to be able to confirm the acute vascular impacts of the use of an e-cigarette. In addition, the vascular and metabolic impacts due to the potential toxicity of the other components of these e-cigarettes could be investigated. Finally, the comparison between patients who are smokers and occasional smokers will provide a better understanding of the different acute and chronic effects of nicotine.

Inclusion Criteria:

• Subject between 18 and 40 years old.
• The subject must be a regular smoker (more than 1 cigarette per day for 2 years) OR be an occasional smoker (between 1 and 15 cigarettes in his life).
• The subject must be able to sign a free and informed consent, and to follow the instructions.
• Complete visual examination within the last 5 years.

Exclusion Criteria:

• Narrow iridocorneal angles.
• Inadequate or contraindicated pupil dilation.
• Insufficient visual fixation.
• Ametropia greater than -6 and +6 δ.
• Known hypersensitivity or allergy to any component of the ophthalmic formulation used, including benzalkonium chloride (preservative) and components of the vaping liquid.
• Eye trauma or eye surgery in the last 6 months.
• Evidence of present or recent infection or inflammation in both eyes.
• The use of ocular or systemic medication 30 days prior to the study.
• Presence of ocular pathology (corneal oedema, severe keratoconjunctivitis sicca, advanced cataract, retinopathy, glaucoma).
• Systemic disease (uncontrolled diabetes, myasthenia gravis...) or pulmonary, cardiac, hepatic, renal, endocrine problems.
• History of epilepsy and psychiatric: schizophrenia, bipolarity, anxiety, depression.
• Being pregnant or breastfeeding.
• History of alcohol abuse.
• History of drug or psychotropic use.