The document discusses various corrective lenses and advanced vision technologies including single vision, bifocal, and multifocal lenses, as well as modern innovations like smart glasses and smart contact lenses. It highlights the functions of these devices, such as correcting refractive errors and providing augmented reality experiences. Additionally, it mentions LASIK surgery as a laser treatment option for vision correction.

1. CORRECTION OF REFRACTIVE ERROR

2. SPECTACLE CORRECTION

3. Single vision lenses
Single vision lenses have one dioptric power throughout the entire lens.
They can be used to correct vision in either near or far viewing situations, which
is why single vision lenses form the basis of both distance glasses and reading
glasses.
Can also be used to correct astigmatic patients
Can be made photochromatic thus protecting the patient from the light.

4. Bifocal lenses
Bifocal lenses are used for people who are both nearsighted and
farsighted.
It is common for people who are over the age of 40 to begin to notice a
change in their vision and require the need for bifocals.
As we age, our eyes begin to have trouble focusing on objects at
different distances away.

5. Multifocal lenses
Multifocal lenses allow you to see at multiple distances, because they
have different sections for viewing close up, far away and everything in
between.
 Whether you're driving, using a computer, shopping or reading, you can
usually wear one pair of multifocal to accommodate most of your vision
needs.

6. Contact lenses
correction

11. MODERNTECHNOLOGY
IN REFRACTIVE ERROR
CORRECTION

12. Hybrid contact lenses
A hybrid lens is designed with a rigid gas permeable center and a soft skirt.
This provides the comfort of a soft lens with the clear vision of a gas permeable lens.
Good candidates for hybrid lenses include: Those with regular corneal astigmatism.

13. Smart glasses
• Smart glasses are a form of augmented reality.
• Augmented Reality: Adds senses to the existing, real environment.
• Integration of virtuality into the tangible world.
• Wearable computer in the form of glasses.
• There are various brands of smart glasses e.g. google glasses, ray bun, amazon
glasses etc.

14. Smart glasses
• First prototyped in late 2012 and google glasses was the first break through.

15. Functions of smart glasses
• Smart Glasses integrates a computer, cameras, and sensors in order
to deliver the augmented reality experience.
• Similar to the components of a smartphone: receiving calls, taking pictures,
sensors, GPS, speakers, video chart, Wi-Fi and Bluetooth services etc.
• Eye tracking helps to determine what the user is looking at
• Mini projectors help to cast virtual 3D objects into the real world.

16. Purpose for smart glasses
• Navigate the user on roads or indicate speeding
• Universal remote control with compatible devices through hand gestures
• Sighted companion for blind people by giving them information through
vibrations
• Students can view textbooks and virtual 3D worlds
• Can display performance measurement and comparison

17. smart contact lenses
• Contain different types of lenses depending on their purposes.
• Transition lenses: Contact lenses that darken automatically in sunlight to
reduce glare and enhance comfort.
• . The lenses feature a photochromic filter that continuously adjusts the amount
of light entering the eye.
• They automatically return to a regular tint in normal or dimly lit
environments.

18. Augmented reality lens
• A smart contact lens with a built-in visual display is designed to magnify images for
people with low vision. They also integrate human computer interface control.
• The patented lens, designed by a company called Mojo Vision, can project content
from a smartphone.
• Multiple lenses: are also used to restore vision in children and teens with myopia
(nearsightedness).
• These differ from existing OrthoK contact lenses, which reshape the cornea, by
redirecting how light hits the retina. Also, the new lens does not need to be worn
overnight.

19. Refractive surgery – LASIK surgery
• Lasik surgery: Laser – Assisted In Situ Keratomileusis
• It is a laser Tx applied to the cornea used to treat most cases of myopia,
hyperopia and astigmatism.
• Once the procedure is done the px can see as good as with glasses
• A bandage contact lens is inserted once the procedure is done as the cornea
self heal.

20. The end
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