Contrast sensitivity in a large adult population

Area of Science:

• Ophthalmology
• Visual Science
• Optometry

Background:

• Contrast sensitivity is crucial for visual function.
• Establishing population-specific norms for contrast sensitivity is important for accurate clinical assessment.
• Previous research has explored factors influencing contrast sensitivity, but local population data is often limited.

Purpose of the Study:

• To determine the normal spatial Contrast Sensitivity Function (CSF) distribution in a healthy Republic of Singapore Air Force (RSAF) population.
• To investigate associations between contrast sensitivity and various factors including refractive error, occupation, sex, age, and race.
• To provide a local normogram for contrast sensitivity assessment.

Main Methods:

• A consecutive sample of 1612 eyes from 807 RSAF personnel with no known ophthalmic disorders underwent contrast sensitivity testing using Vistech charts.
• Refractive errors were corrected to ensure a visual acuity of 6/6 or better.
• Data were analyzed using multiple regression to assess independent associations.

Main Results:

• Myopes exhibited lower mean contrast sensitivity at higher spatial frequencies compared to emmetropes.
• Pilots and aircrew demonstrated better performance than ground crew.
• Females showed lower spatial contrast sensitivity than males.
• Age was associated with reduced sensitivity at lower spatial frequencies, while Chinese individuals had lower sensitivity at higher frequencies compared to other races.

Conclusions:

• Myopia, sex, age, occupation, and race are significantly associated with contrast sensitivity in this RSAF population.
• The findings underscore the necessity of utilizing population-specific normograms for contrast sensitivity evaluation.
• Target acquisition training may enhance contrast sensitivity, and micro-amblyopia is a potential factor in reduced sensitivity among myopes.