Optometric Abbreviation

AC- Anterior Chamber (between Cornea and Iris, filled with transparent liquid- Aqueous humour)

Acc- Accommodation(mainly occur in case of near vision)

ACT- Alternate Cover Test

Add- Addition (additional plus spherical power needed to improve near work)

AL- Axial Length

APCT- Alternate Prism Cover Test

APD- Afferent Pupillary Defect

ARMD- Age Related Macular Degeneration (usually occurred above 50 yrs age) 

BE- Both eyes

BVD- Back Vertex Distance (back surface of the spectacles to front surface of cornea)

CT- Cover Test

DC- Diptres Cylinder

DS- Dioptres Sphere

DV- Distance Vision

h/o- history of

IOL- Intra Ocular Lens (artificial lens which is implanted after cataract surgery)

IOP- Intra Ocular Pressure (fluid pressure inside the eye)

LP- Light Perception(it is measurement of visual acuity-when patient is unable to see hand movements)

LVA- Low Vision Aid(devices which improve visual performance)

NLP- No Light Perception(total blindness)

NPC- Near Point of Convergence

NV- Near Vision

OD- Doctor of Optometry ; Oculus Dexter (Right Eye)

OL- Oculus Laevus (Left Eye)

OS- Oculus Sinister (Left Eye)

OU- Oculus Uterque (Each Eye)

PD- Pupillary Distance(distance between centre of Right & Left pupil)

PERRLA- Pupils Equal, Round, Reactive to Light & Accommodation

PGP- Previous Glass Prescription

PL- Perception of Light

Px- Patient

RAPD- Relative Afferent Pupillary Defect

Rx- Prescription

SCL- Soft Contact Lens

Sx- Symptoms

TBUT- Tear Break Up Time

VA- Visual Acuity(spatial resolving power of the eye)

Ocular Injuries

Any kind of eye injury is known as Ocular Injury. The visual impairment as a result of an eye injury may vary from slight reduction in visual acuity to total blindness.

A) Mechanical Injuries-

1) Contusion Injuries: It may results from flying blunt objects(e.g. ⚽)

2) Perforation Injuries: It may results from sharp objects(e.g. 🖉)

B) Non-mechanical Injuries-

1) Chemical Injuries: Most of the chemicals are harmful to eyes. Ex- Acid, Alkali etc.

The severity of the burn depends on the concentration of the chemical, the exposure duration & the pH of the solution. All solutions are irritating to the eye, but is rarely serious if their pH is  ≥ 2.5 . Alkali burns are more severe than acid burns.

Apart from acids & alkalis there are few other chemicals like Organic Solvents(e.g. alcohol), Surfactants(e.g. soap), Irritants & Allergens(e.g. pollen) & Aerosols(e.g. deodorant) which are also harmful.

Ideal treatment is to neutralize the chemical. Immediate & prolonged irrigation with normal water should be carried out. 

2) Electrical Injuries: The main sources of electrical injuries are lightning & high voltage electrical appliances.

3) Radiation Injuries: The major natural source of electromagnetic radiation is sun. Fortunately, the atmosphere acts as a filter, absorbing a significant amount of the harmful radiation. The highest intensity of radiation that penetrates the atmosphere is in the visible range(400-800nm). The effect of radiation will depend upon the wavelength of the radiation & the photon energy.

• Long wavelength radiation has low photon energies. Infra-red radiation has 0.01 to 1 eV(electron volt) range

• Visible & short wavelength radiation have higher photon energies. For visible & UV radiation, the photon energy range is 1 to 4 eV.

4) Thermal Injuries: There are 2types of thermal injuries- flame( e.g. oven) & contact burns(e.g. molten metal).

All types of eye injuries- mandatory check up by an Ophthalmologist. 

Preventive Measures: A detailed history taking at the time of Vision test is very important. Few examples-

• Sportsperson- We will recommend Contact Lens or for Spectacles user high impact resistant lens material like MR8 /Polycarbonate 
• Two-wheeler Rider- Anti Reflection Coating lens to improve vision clarity by reducing unwanted light reflection. 
• Occupational (Mechanical Engineer)- Safety goggles is mandatory.

Also parents should educate their children regarding possible ocular hazards.

 

Colour Vision

 

Colour Vision is the ability to distinguish among different colours. The sensation of colour is subjective. Individuals are taught names for their colour sensations and subsequently use these names whenever the same sensation is obtained. By the age of 3 a child can correctly identify a colour. So, Colour Vision Test can be done at the age of 3.

There are 3 types of Photoreceptor cells in Retina-

1) Red Sensitive

2) Green Sensitive

3) Blue Sensitive

which combinedly perform the function of Colour Vision. 

In Colour Vision Deficiency(CVD) which is more commonly known as Colour Blindness, sensation of one or more primary colours(Red, Green & Blue) is either defective(anomalous) or absent(anopia).

Importance of Colour Vision:

Colour Vision defects can affect learning abilities and reading development. It also can limit career choices.

 

Importance of Eyes

 

Eyes are one of the most precious organ of human body. It is most important organs of sense since we human beings perceive approximately 80% of all impressions through sense of sight. But unfortunately we tend to neglect to maintain its heath. 

How to maintain Healthy Eyes:

1) Regular eye check up- once in a year

2) Use Spectacles or Contact Lens or Sunglass(power sunglass) of latest prescription

3) Eat healthy foods- specially Vitamin A,C,E and omega-3 fatty acid enriched foods

4) Use sufficient light at the time of near work like Reading, Writing and Sewing etc.

5) Regular exercise and sufficient sleep(approx. 8hrs.)  

           Healthy Eyes →Good Vision →Good Performance →Mental Satisfaction