LY-23NS Near vision acuity chart (Distance: 30cm)
Specifications:
1.It's one-sided.
2.It's vertical.There is also horizontal style.Please see below link:
http://www.jhoptical.com/LY-23N.html
3.Test distance is 30cm .Led illuminated near vision acuity. It's for weak sight,hyperopia and presbyopia testing.
Features:
1.Using high-tech light-emitting,power saving,slim and accuracy testing.
2.High brightness and uniform light-emitting make every chart be with consistent brightness contrast.It ensures accuracy testing.
3.LED photoelectric conversion efficiency is more than 80%.the same brightness of the light just around 10% of the electricity needed to traditional fluorescent lamp.
4.Protect eyesight: DC drive, no flash(Normal lights are AC drive, it will inevitably produce strobe).
5.Health: Healthy light contain ultraviolet and infrared light, no radiation (ordinary light contains ultraviolet and infrared).
6.Green: no mercury,xenon or other harmful elements, and will not produce electromagnetic interference (ordinary lamp contains mercury and lead elements, electronic ballasts will produce electromagnetic interference).
7.Long life: life of up to 100,000 hours.
8.Safety factor: safety voltage, current, and smaller, less heat, no security risk.
Packaging Detail: 29cm x 20cm x 6cm, 0.55kg