Estimating Visual Acuity Without a Visual Acuity Chart.

Purpose: This study explored whether visual acuity (VA) can be inferred from self-reported ability to recognize everyday objects using a set of yes/no questions.

Methods: Participants answered 100 yes/no questions designed to assess their ability to recognize familiar objects at typical viewing distances, such as distinguishing between a full moon and a half moon on a clear night. The questions demanded VA ranging from normal to severe vision impairment.

Pattern-reversal visual evoked potentials in prosthetic vision and simulated visual reduction.

Objective: To quantitatively evaluate visual evoked potentials (VEPs) in prosthetic vision and simulated visual reduction.

Methods And Analysis: Four blind patients implanted with the Argus II retinal prosthesis and seven sighted controls participated. VEPs were recorded with pattern-reversal stimuli (2 cycles of a horizontal square wave grating, 0.

The effect of illumination on the visibility of steps and ramps for people with low vision.

Significance: Poor visibility of indoor features such as steps and ramps can pose mobility hazards for people with low vision. For purposes of architectural design, it is important to understand how design parameters such as the illumination level of an indoor space affect the visibility of steps and ramps.

Purpose: This study was aimed to examine the effect of typical variation in photopic illumination level in an indoor space on the visibility of steps and ramps for individuals with low vision.

Urgent support mechanism: saving millions of COVID-19 vaccines from expiry in Africa.

Delivering COVID-19 vaccines with 4-6 weeks shelf life remains one of Africa's most pressing challenges. The Africa Centres for Disease Control and Prevention (Africa CDC) leadership recognised that COVID-19 vaccines donated to many African countries were at risk of expiry considering the short shelf life on delivery in the Member States and slow vaccine uptake rates. Thus, a streamlined rapid response system, the urgent support mechanism, was developed to assist countries accelerate COVID-19 vaccine uptake.

Customizing spatial remapping of letters to aid reading in the presence of a simulated central field loss.

Reading is a primary concern of patients with central field loss (CFL) because it is typically performed with foveal vision. Spatial remapping offers one potential avenue to aid in reading; it entails shifting occluded letters to retinal areas where vision is functional. Here, we introduce a method of creating and testing different remapping strategies-ways to remap text-customized for CFL of different shapes.